1. Heat the oven to 180C/160C fan/gas 4. Grease and line a baking tin approx 30cm x 20cm with baking parchment. In a large bowl, cream together the butter and sugar until light and fluffy. In a separate bowl, beat together the eggs, milk and Dr. Oetker Vanilla Extract, then add to the butter mixture. Add the flour, Dr. Oetker Baking Powder and Dr. Oetker Fine Dark Cocoa Powder to the mixture, then mix until smooth.
2. In a small bowl, coat the Dr. Oetker Milk Jumbo Choc Chips, Dr. Oetker Dark Jumbo Choc Chips and Dr. Oetker White Chocolate Chunks in a little flour, then fold through the mixture – coating the chocolate pieces in flour will prevent them from sinking to the bottom of the cake and will allow them to disperse evenly through the batter.
3. Pour the cake mixture into the prepared tin and spread evenly. Bake for 35-40 mins, until an inserted skewer comes out clean. Leave to cool in the tin for 15 mins, then remove from the tin and cool on a wire rack. Once cool, spread the Dr. Oetker Rich Chocolate Buttercream Style Icing over the top using a palette knife. Decorate with the Dr. Oetker Bright & Bold Sprinkle Mix and use the Dr. Oetker Letters & Numbers to spell out your special message.