Preheat your oven to 350°F (175°C) and prepare a baking dish.
In a large bowl, combine the flour, sugar, cocoa powder, baking powder, and salt.
Add the softened butter and egg to the dry ingredients, mixing until combined.
Spread the dough evenly into the prepared baking dish.
Bake for 15-20 minutes until the edges are set but the center remains slightly soft.
While the base cools, prepare the cannoli filling by mixing the ricotta cheese, powdered sugar, vanilla, cinnamon, and chocolate chips.
Once the base cools, spread the filling over the top in an even layer.
Chill the assembled squares in the refrigerator for at least an hour to set.
Cut into squares and serve as dessert.