Preheat your oven to 350°F (175°C) and grease a 12-cup bundt pan with cooking spray or butter.

Cut each refrigerated biscuit into four equal pieces, totaling 64 chunks.

Combine 1/2 cup granulated sugar and 1 teaspoon cinnamon in a large zipper bag. Add biscuit pieces, seal, and shake until well-coated.

Layer the coated biscuit pieces into the greased bundt pan and sprinkle fresh blueberries between the layers.

Melt 1/2 cup unsalted butter in a microwave-safe bowl, then stir in 1/4 cup granulated sugar, 1/4 cup brown sugar, and 1 teaspoon vanilla extract until smooth.

Pour the melted butter mixture over the layered biscuits and blueberries in the bundt pan.

Bake for 40-45 minutes until the top is golden brown and the center is firm.

Let cool for 10 minutes, then invert onto a serving plate to release.