Preheat the oven to 350°F. Grease a 12-cup Bundt pan with nonstick cooking spray or shortening.

Open both cans of biscuits, split the biscuits apart, and cut each one into 4 pieces. From two 8-count cans you will have 64 pieces total.

In a large zip-top bag, combine 1/2 cup of the granulated sugar with the cinnamon. Add the biscuit pieces in batches, seal the bag, and shake until each piece is evenly coated. Transfer the coated pieces to the prepared Bundt pan.

As you arrange the dough pieces in the pan, scatter the blueberries over and between them. When all the dough is in the pan, sprinkle any remaining cinnamon sugar over the top and press any remaining blueberries into the surface.

Melt the butter in a microwave-safe bowl, then whisk in the remaining 1/2 cup granulated sugar, the brown sugar, and the vanilla until smooth. Pour this mixture evenly over the biscuit pieces and blueberries in the pan.

Bake on the middle oven rack for 40 to 45 minutes, until the top is browned and the center dough feels firm to the touch. Let the pan cool on a wire rack for 10 minutes, then invert the monkey bread onto a large plate. The berries will be hot, so let it rest briefly before serving warm.