I started making crumble topping because my favorite sweet potato casserole (which I've made every year for Thanksgiving for over a decade!) has a streuseled topping. Since then, I've tended to keep extra topping in the freezer, because it makes for super easy fruit crisps and crunchy cakes and cupcakes. In fact, any time I make a recipe that calls for some kind of crispy topping, I usually ignore that part of the recipe and head for my freezer instead.
I'm not a fan of flour in my topping because I feel like it doesn't cook properly and tastes like raw flour - yuck! Instead, I use oats, and I've found that the quick cooking kind is even better than regular rolled oats. I've also never been very good at cutting butter into pastry, so I use my food processor instead. We have a nut-free house because of allergies, but I think walnuts or pecans would be a really nice substitute for some of the oats.
Easiest Crumble Topping
1 heaping cup quick cooking oats
1/2 cup sucanat
1/2 cup brown sugar
1/2 cup cold butter (1 stick), cut into small pieces
1. In the bowl of a food processor, combine the oats, sucanat and brown sugar. Pulse a few times until ingredients are well-mixed.
2. Scatter the butter over the oat-sugar mixture and pulse several times until the butter is incorporated and the mixture clumps together. Keep cold in the fridge or freezer until ready to use.
the dry ingredients in the food processor
the finished crumble
the crumble topping on an apple cake