This is a great all-purpose streusel recipe for baking on top of pies. It makes large clumps that bake up slightly crisp on the outside, then soft in the middle. You can add other ingredients to your streusel to flavor it—sometimes I add a splash of vanilla or almond extract, and I often throw in additional spices like cloves, nutmeg, or ginger.
In a medium bowl, stir the oats, all-purpose flour, whole-wheat flour, brown sugar, baking powder, salt, and cinnamon to combine. Cut the butter into tablespoon portions and drop them into the bowl. Mix with your hands or a pastry cutter until the mixture comes together to form large clumps.
To use, crumble the streusel over the top of a pie that requires baking and bake as the recipe instructs. If the topping is browning too quickly, tent it with foil for the remainder of the bake time.
I always have three kinds of hot sauce in my purse. I have a soft spot for making people their favorite dessert, especially if it's wrapped in a pastry crust. My newest cookbook, The Book on Pie, is out on November 10th, 2020.