This recipe can be adapted to make any fruit crumble, just buy frozen fruit and have fun experimenting.
2 tablespoons quick oats
2 tablespoons brown sugar
1 tablespoon flour
1/8 teaspoon ground cinnamon
1 tablespoon cold unsalted butter
3/4 cup frozen berries
Vanilla yogurt, for serving (optional)
Combine the oatmeal, sugar, flour, and cinnamon in a large mug. Use a fork to cut in the butter until the texture is crumbly. Place the berries on top and microwave on high for 2 minutes, until the fruit bubbles and thickens. Stir to bring the crumble to the surface and serve with a scoop of vanilla yogurt on top.
Recipe adapted from foodnetwork.com