Preheat the oven to 375 degrees F (190 degrees C). Grease an 8-inch square pan, and line with parchment paper with overhang.
In the bowl of a food processor, add flour, baking powder, salt, and cinnamon. Also, add in white and brown sugar. Pulse it a couple of times to mix the dry ingredients.
Add cold, cubed butter, and process until the dough looks coarse and crumbly. If you try to squeeze some dough in your hands, it should clump together. Alternatively, you can add all the dry ingredients in a medium bowl. Use a fork or pastry cutter to blend in the cubed butter until you have a crumbly dough.
Reserve 3/4 cup of the dough for the crumble topping. Pat the rest of the dough into the prepared pan. Bake the crust for 10 minutes.
Remove the baking pan after 10 minutes. Let it rest for 5 minutes.
Spread the jam all over the baked crust leaving about 1/8 inch space from the edges of the crust.
Crumble the remaining reserved dough over the jam.
Bake in a preheated oven for 35 minutes, or until the topping is golden brown. Transfer the pan to a wire rack, cool completely before cutting into squares.