Line a 18 x 28cm slice tin with baking paper. Make sure you leave plenty of paper hanging over the edges to help you remove the cooked slice from the tin.
Preheat your oven to 180 degrees
Place the butter, sugar, flour and baking powder into a food processor and mix until all the ingredients have just combined. Then add the egg yolk and continue to process until a soft dough forms.
Spoon the dough into the prepared slice tray and smooth the surface - it will feel like you don't have enough mixture (I was freaking out!) but if you use two spoons to spread it, you will cover the surface. Place the slice tray into the preheated oven and bake for 12 - 15minutes or until the base has turned golden brown. Remove from the oven and allow the slice to cool for five minutes.
Add the raspberry jam to the cooled sliceand make the topping.
To make the topping, lightly beat the egg before adding it to a bowl with the sugar and coconut. Mix the ingredients together well and sprinkle over the jam.
Place the slice tray back into the oven to bake for 25 minutes or until the top turns golden brown.
Allow the slice to cool in the tin before carefully transferring it to your bench top to cut into pieces.