Easy Blueberry Skillet Cake

For the streusel topping: Combine the almonds, sugar, 2 tablespoons butter, flour and cinnamon in a food processor and pulse until large crumbs form. For the coffee cake: Preheat the oven to 375 °F. In a 9-inch cast-iron or other ovenproof skillet, cook the remaining 2 tablespoons butter and brown sugar over medium heat until melted. Arrange the biscuits in a single layer in the skillet. Scatter the blueberries over the biscuits, and then distribute the streusel topping over the berries. Bake until the biscuits are golden and a tester inserted in the center of a biscuit comes out clean, about 30 minutes. Allow to cool slightly and serve from the skillet.