In a large bowl toss together:
2 tsp baking powder
2 cups flour
1 cup brown sugar
use your hands to combine dry ingredients.
1 1/2 cup butter, cut into small cubes
This mixture should hold together when squeezed in your fist.
Divide crumble mixture in half and press half inthe the bottom of a greased 9x13 pan.
Filling:
1 cup chocolate chips
1/2 evaporated milk
1 cup Nutella
Combine in a double boiler and melt until smooth. Don't let mixture get too hot, remove from heat as soon as chocolate melst and blend until smooth.
Pour filling over crumble mixture. Top with remaining crumb mixture, breaking it into small pieces with your fingers. Bake for 40 minutes at 350 until golden brown.
Prepare for your new addition!