Rainbow cookie pie

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

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

Filling

• 1kg (2Ib 4oz) white chocolate spread (or 1kg/2Ib 4oz white chocolate mixed with 80ml/5½ tbsp 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 (Bin) round cake tin, lined
• Piping bag and open star nozzle

METHOD

1. 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.
   
   
2. 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.
   
   
3. 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 (lin) from the top. Cover and set aside the remaining cookie dough.
   
   
4. 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.
   
   
5. Preheat the oven to 195°C (175°C fan/385° F/Gas 5½).
   
   
6. 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.
   
   
7. 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.