step 1
Heat oven to 180c.
step 2
Cream butter and both sugars.
step 3
Stir in egg and vanilla until smooth. Add milk chocolate chips, flour and baking powder and mix until you have a sticky dough.
step 4
Spoon dough into a cake tin and smooth surface.
step 5
Bake for 15-20 minutes.
step 6
Spread over chocolate spread to 2cm of the edge. Sprinkle over white chocolate chips and return to the oven for 5-7 minutes.
step 7
Best served warm with ice-cream.