Lauren and Rachel say: “Perfect for any birthday party, this cookie pie has bright layers of rainbow chocolate inside our original chewy cookie recipe, topped with M&Ms and sprinkles.”

Serves 8 or 12

Ingredients

For the cookie dough:

• 190g (1 stick plus 4 tbsp) unsalted butter
• 150g (¾ cup packed) light soft brown sugar
• 150g (⅔ cup) caster sugar
• 1 egg plus 1 egg yolk
• 300g (2½ cups) plain flour
• 1 tsp baking powder
• 40g (2 tbsp) golden syrup
• 60g (2¼oz) bake-stable sprinkles, plus extra for topping
• 60g (2¼oz) M&Ms, plus extra for topping
• 150g (5½oz) white chocolate chips

For the filling:

• 1kg (2lb 4oz) white chocolate spread (or 1kg white chocolate mixed with 80ml vegetable oil)
• Pink, orange, yellow, green, blue, indigo and violet oil-based food colourings
• Decoration (optional)
• 100g (6½ tbsp) unsalted butter
• 180g (1⅓ cups) icing sugar
• 3–5 drops of vanilla extract

Special equipment:

• Mixer or hand-held electric whisk
• 20cm (8in) round cake tin, lined
• Piping bag and open star nozzle

Method

To make the cookie dough, put the butter and both sugars into a mixer and, using the paddle attachment, cream together on a high speed (or use a hand-held electric whisk). Add the egg and yolk and mix.

Sift in the flour and baking powder, then add the remaining cookie dough ingredients. Combine slowly until a dough forms and the sprinkles, M&Ms and chocolate chips are evenly distributed.

Press a thick layer of dough evenly into the bottom of the lined tin. Press more mixture around the sides of the tin and leave a gap about 2.5cm (1in) from the top. Cover and set aside the remaining cookie dough.

Melt the white chocolate spread (or white chocolate mixed with oil) in a bowl in the microwave and divide between seven bowls. Use the oil-based food colourings to colour each bowl a colour of the rainbow. Carefully pour the last rainbow colour (violet) into the cookie base and set in the freezer until tacky (about 10 minutes). Repeat with each colour, finishing with pink. Return to the freezer.

Preheat the oven to 195°C (175°C fan/385°F).

After at least 30 minutes in the freezer, remove the tin and use the remaining cookie dough to make a lid, place it on top and seal the edges. Push some extra M&Ms into the top along with a handful of sprinkles. Bake for 30 minutes. Leave to cool completely in the tin, then chill in the fridge overnight.

Slice the pie evenly into 8 or 12 pieces. If decorating with buttercream, whip the butter on a high speed until whitened. Sift in the icing sugar, add the vanilla extract and mix until combined. Load a piping bag with an open star nozzle and pipe whips on top of each slice. Finish with more sprinkles and M&Ms. 

Lauren and Rachel say: “This light yet moist pink sponge is laced with champagne (or prosecco), decorated with colourful edible flowers and finished with buttercream blooms – perfect for a summer’s day celebration.”

 Makes a 20cm (8in), 3-layer cake

Ingredients

• 540g (4 sticks plus 4 tbsp) unsalted butter
• 650g (3¼ cups) caster sugar
• 9 egg whites
• 120ml (scant ½ cup) soured cream
• 250ml (generous 1 cup) champagne or prosecco
• 2 tsp vanilla extract
• 650g (5 cups) self-raising flour
• ½ tsp bicarbonate of soda
• Pink gel food colouring

For the filling:

• 250g (2 sticks) unsalted butter
• 450g (3¼ cups) icing sugar
• 50ml (3½ tbsp) champagne or prosecco
• Vanilla extract or strawberry flavouring, to taste
• Orange gel food colouring

Decorations:

• 500g (4 sticks plus 2 tbsp) unsalted butter
• 800g (6⅔ cups) icing sugar
• 2–3 tsp whitening powder (optional)
• Vanilla extract or strawberry flavouring, to taste
• Food colouring gel of your choice
• Gold nonpareils
• Edible flowers

Special equipment: 

• Mixer or hand-held electric whisk 
• 3x20cm (8in) cake tins, lined
• 28cm (11in) cake drum, turntable and dowels (optional)
• Piping bags and nozzles

Method

Preheat the oven to 180°C (160°C fan/350°F/Gas 4).

Put the butter and sugar into the bowl of a mixer and, using the paddle attachment, cream together on a high-speed setting (or use a mixing bowl and a hand-held electric whisk). Once the butter has turned pale, add the egg whites, one by one, on a medium speed setting. Scrape down the sides with a spatula and re-mix.

Combine the soured cream, Champagne and vanilla extract (the wet ingredients) in a jug. Sift the flour and bicarbonate of soda into another bowl (the dry ingredients).

Add about one-third of the wet ingredients to the butter and sugar mixture and beat to combine, then add one-third of the dry ingredients and beat again. Repeat until everything has been added, finishing with the last of the dry ingredients.

Add the pink colouring until your desired shade has been reached. Beat for 30 seconds until fully incorporated.

Divide the pink batter evenly into the lined tins and bake for 35–40 minutes, or until the sponges bounce back when pressed. Leave to cool in the tins for 10 minutes, then turn out onto to wire racks and leave to cool completely.

Filling and stacking

Make a batch of plain butter cream using the quantities listed. Add the butter to the bowl of a mixer and whip on a high speed for 5–10 minutes first. Scrape down the sides of the bowl with a spatula and whip for another 30 seconds. This will turn the butter more white than yellow. Sift the icing sugar into the bowl and combine on a medium setting, remembering to stop and scrape around the sides to mix in everything fully. Add the champagne or prosecco and either vanilla extract or strawberry flavouring – this goes well with fizz! We also added some orange food colouring. Chill in the fridge for 30 minutes as the liquid will make the buttercream soft.

Level and stack the cake using the buttercream as the filling. Level a cake by cutting the unwanted dome off the top to make it completely flat. Smear a small amount of buttercream onto a cake drum / board and stick the first layer of the cake down. Pipe a buttercream ring 1cm in from the perimeter on all but one of the sponge. Chill the sponges in the fridge or freezer for 10–15 minutes or until the rings have solidified – these “dams” will act as a barrier to stop softer fillings spilling out over the edges of your cake. Spoon in your filling of choice.

For the top layer of your cake, always turn the final sponge layer over so that the level bottom of the sponge becomes the top of the cake. Place the cake in the fridge for 15–20 minutes to set the buttercream before decorating.

Chill the cake for 10 minutes until solid. Crumb coat with the remaining buttercream by loading buttercream on a palette knife and pull it around the edges of the chilled cake, adding more buttercream and roughly smoothing it down until the entire side of the cake is covered. Pile some more buttercream on top of the cake and smooth down to the edges using the palette knife. Working quickly, use a cake scraper to take off any excess buttercream, and smooth what is left around the sponge. Smooth down the ragged edge at the top of the cake using a palette knife, before giving the cake a final once over with the cake scraper. Chill the cake until the buttercream has stiffened up. Return to the fridge for another 30 minutes or until ready to decorate.

Decoration

Make a batch of plain buttercream (as above) using the quantities listed here and adding whitening powder, if using, then flavour to suit your taste. Load a piping bag and snip off the end with a pair of scissors. Apply and smooth the buttercream over the top and sides of the cake (as above), paying special attention to the top as this will be the focal point of the cake. Save the excess buttercream to decorate. Chill in the fridge for 1 hour.

Remove the cake from the fridge and use a sharp knife to make sure the top is flat and then cut the very edge of one side of the cake off, so it can sit flat on its side. Use a cake lifter to position the cake on its new flat edge, refrigerate and then smooth more buttercream over any imperfections and the back of the cake. Use a straight-edge scraper to smooth.

Use a sharp knife to carve lines into the side of the cake (which was the top) and the curved edges of the sides. These will be the stems of the buttercream flowers. Use some excess buttercream and colouring to the match theme of the cake – we have used pink and orange. Pipe a small blob of buttercream using a piping bag and gently drag into a petal shape using a palette knife, repeating in a circular pattern with five petals in total, creating a daisy. Dainty blobs and smaller palette knives will allow more delicate-looking flowers. Petal nozzles can also be used to create different flowers – go as complicated as you dare (our favourites are simple ones though). Use the gold nonpareils for the centre of the flowers.

Refrigerate any leftover buttercream for a future project.

Apply the edible flowers just before serving; edible flowers will stay fresh in the fridge but wilt if left out for too long, so are best added on the day of the event. Attach using a small amount of buttercream, royal icing or edible glue, using a paintbrush to smooth down any petals that stick awkwardly.

Lauren and Rachel say: “Blondies are definitely one of our bestsellers and our Cherry Bakewell ones are a personal favourite! Fudgy pieces of white chocolate and almond, swirled with cherry jam and filled with glacé cherries; every bite is a Bakewell lover’s dream!”

Makes 8–10

Ingredients

• 220g (2 sticks) unsalted butter
• 125g (4½oz) white chocolate
• 3 eggs
• 125g (⅔ cup) caster sugar
• 125g (½ cup plus 2 tbsp) light soft brown sugar
• 40g (2 tbsp) golden syrup
• Pink gel food colouring (optional)
• 5–10 drops of almond extract, to taste
• 285g (2 cups plus 2 tbsp) plain flour
• 1 heaped tsp cornflour
• 1⁄4 tsp salt
• 200g (7oz) white chocolate chips
• 150g (5½oz) glacé cherries
• 180g (6oz) cherry jam or conserve

Special equipment: 

• Mixer or hand-held electric whisk
• 20x30cm (8x12in) tin, lined
• Piping bag

Method

Preheat the oven to 200°C (180°C fan/400°F).

Using a microwave, or over a bain-marie, melt the butter and white chocolate together.

Combine the eggs, both sugars, the golden syrup and a little pink food colouring, if using, in a mixer. Add the melted chocolate mixture. Scrape the mixture around the sides and bottom with a spatula before mixing again.

Pour in the almond extract, to taste. Sift the flour and cornflour together and pour into the wet mixture. Add the salt and 150g (5½oz) of the chocolate chips, mixing on a low-speed setting and remembering to scrape down the sides with a spatula to make sure all the ingredients combine.

Fold in 100g (3½oz) of the glacé cherries with a spatula. Pour the batter into the lined tin and load a piping bag with the cherry jam. Snip off the tip of the piping bag and pipe lines of jam into the batter. Use a skewer to drag the jam in circles, making sure it is evenly spread. Scatter over the remaining white chocolate chips and press in the remaining cherries.

Bake for 35 minutes. It may look under-baked and the middle should still wobble when it comes out of the oven. Leave to cool completely in the tin, then chill in the fridge for at least 6 hours or overnight before cutting into squares or rectangles to serve.

Top tip: Use bake-stable white chocolate chips in the blondie mixture to ensure they don’t melt while baking. 

Finch Bakery: Disco Bakes And Party Cakes by Lauren and Rachel Finch (£20, DK) is out now