14 oz cold butter, cut into pieces
3 cups all-purpose flour
3 cup oats
2 cup packed brown sugar
2 teaspoon baking powder
1/2 teaspoon kosher salt
24 oz raspberry or other preserves
Preheat the oven to 350 degrees. Butter a half sheet pan lined with parchment.
Mix together the flour, oats, brown sugar, baking powder, and salt in the bowl of a food processor, and pulse a few times to grind the oats.
Add the butter and pulse until it resembles coarse crumbs. Pulse again until it just starts to clump together.
Sprinkle half the mixture into the sheet pan and pat it down evenly.
Smooth the preserves evenly over the surface.
Crumble the other half of the oat mixture over the top and pat down lightly.
Bake until light golden brown on top, about 30 to 40 minutes.
Remove from the oven and let cool in pan. Cut into squares when cool.