Ingredients:

  • 4 cups frozen razzleberry mix (raspberries and blackberries)
  • 1/2 cup granulated sugar
  • 2 tbsp cornstarch
  • 1 tbsp fresh lemon juice
  • 1 tsp vanilla extract
  • 1 cup old-fashioned rolled oats
  • 3/4 cup all-purpose flour
  • 1/2 cup packed light brown sugar
  • 1/2 tsp ground cinnamon
  • 1/2 cup unsalted butter, cold and cubed

Instructions:

  1. In the slow cooker, combine the frozen razzleberry mix, granulated sugar, cornstarch, lemon juice, and vanilla. Stir gently until berries are evenly coated and spread into an even layer.
  2. In a separate bowl, whisk together the rolled oats, all-purpose flour, brown sugar, and cinnamon.
  3. Add the cold, cubed butter to the dry ingredients. Use a fork or pastry cutter to work the butter in until the mixture resembles coarse crumbs the size of peas.
  4. Sprinkle the crumble mixture evenly over the top of the berry base.
  5. Secure the lid and cook on Low for 6 hours (or High for 3 hours) until the berry juices are bubbling and the topping is toasted.