Hidden heart cake

Slice into this delicious loaf cake and reveal the secret heart design running through the middle – a really romantic bake!

Heat oven to 160C/140C fan/gas 3. Grease a 900g loaf tin and line with a long strip of baking parchment. Cream 175g butter and 175g sugar until light and fluffy. Beat 3 of the eggs and pour in, a little at a time, mixing after each addition. Sift together 140g flour, 1?2 tsp baking powder and the cocoa, then fold into the butter mixture along with the almonds. Combine 100ml milk, 11?2 tsp vanilla and all the food colouring and add to the batter, then mix until evenly coloured.
Pour into the prepared loaf tin and bake for 1 hr 10 mins until a skewer comes out clean. Cool for 10 mins in the tin, then transfer to a wire rack. When cool, cut the cake into 4cm slices. Using a 5cm cutter, stamp out the hearts (save any remaining cake for another treat).
Repeat step 1 to make a second cake mixture – you won’t have cocoa or food colour in this batch. Pour 3?4 of the mixture into the prepared loaf tin. Push the bottoms of the hearts into the batter in a tightly packed row. Spoon over the remaining cake mixture, covering as much of the hearts as possible. bake for 1 hr or until a skewer comes out clean. Cool for 10 mins in the tin, then transfer to a wire rack to cool completely.
For the icing, gently heat all the ingredients over a low heat until combined. Leave to cool, then chill until needed. Spread over the cooled cake and decorate with the sprinkles, if using. Will keep for 3 days stored in a cake tin.