Preheat the oven to 360°F.
For the dough, mix the margarine, sugar, flours, blueberry powder and salt in a bowl using a mixer until obtaining a batter.
Butter a square mold (8×8 inches) and put the dough, pressing against the bottom without leaving any edges. Bake for 10 minutes or until the edges are slightly brown
For the filling, put an egg, sugar, flour and lemon juice in a blender. Blend for 15 seconds and set aside.
Over the previously baked dough, scatter raspberries and grated coconut. Add the blender mixture on top. Bake for 25-30 more minutes until brown and firm.
Allow to cool and cut into squares.