Step 1

Arrange a rack in the middle of the oven and heat the oven to 375ºF. Line the bottom of an 8-inch round cake pan with parchment paper. Lightly coat the pan and paper with cooking spray or butter.

Step 2

Melt 4 tablespoons unsalted butter in the microwave or on the stovetop. Place 1/4 cup of the granulated sugar in a large bowl.

Step 3

Open 1 can biscuit dough and separate the biscuits. For a 12-ounce can, cut each biscuit into 4 pieces. For a 12-ounce can, cut each biscuit into 6 pieces. Roll each piece into a ball and add to the bowl of sugar. Gently toss with your hands until most of the sugar coats the dough balls.

Step 4

Drizzle in 2 tablespoons of the butter and gently use your hands to toss to coat. Transfer the dough balls to the cake pan in a single layer.

Step 5

Place the remaining 1 tablespoon granulated sugar and 6 ounces blueberries in the bowl (no need to clean) and stir with a rubber spatula to combine. Sprinkle evenly over the biscuits.

Step 6

Place 1/3 cup rolled oats, 1/4 cup sliced almonds, 2 tablespoons all-purpose flour, 1 tablespoon packed light brown sugar, 1/8 teaspoon kosher salt, and 1/8 teaspoon ground ginger if desired into the bowl (no need to clean). Drizzle with the remaining 2 tablespoons melted butter and stir until evenly moistened. Sprinkle evenly over the cake and gently press to adhere to the biscuits.

Step 7

Bake until the top is evenly golden and the biscuits are baked through and the center registers at least 195ºF, 30 to 45 minutes. Place the pan on a wire rack while you prepare the glaze.

Step 8

Place 1/2 cup powdered sugar and 1 tablespoon lemon juice or milk into a medium bowl and whisk until a smooth, pourable glaze forms, adding more liquid a teaspoon at a time as needed.

Step 9

Run a thin knife or offset spatula around the cake. Invert a large plate over the cake. Grasping the plate and cake pan in both hands (careful, hot!), flip both over in one motion. Remove the cake pan and parchment paper. Invert a serving plate over the cake, and flip both again so the cake is once again streusel-side up. If any bits of streusel fall off, press back on top. Drizzle with the glaze. Serve while warm, either in wedges or pull-apart style.