Preheat the oven: Preheat the oven to 350°F and generously grease a 10-cup bundt pan with butter or nonstick spray, making sure to coat every groove.
Cut the biscuit dough: Open the cans of biscuit dough and cut each biscuit into quarters using kitchen scissors or a knife. You should end up with small, bite-sized pieces.
Mix cinnamon sugar: In a shallow bowl, stir together the granulated sugar and ground cinnamon until evenly combined.
Coat the dough pieces: Roll each piece of biscuit dough in the cinnamon sugar mixture until fully coated on all sides.
Layer in the pan: Arrange the coated dough pieces in the prepared bundt pan in an even layer, scattering chopped nuts between layers if using.
Make the butter glaze: In a small saucepan over medium heat, melt the butter with the brown sugar and vanilla extract, stirring until smooth and slightly bubbling, about 2 minutes.
Pour glaze over dough: Slowly pour the warm glaze evenly over the layered dough pieces, letting it seep down between the layers.
Bake until golden: Bake for 30 to 35 minutes, until the top is deep golden brown and a toothpick inserted near the center comes out mostly clean with just a few sticky crumbs.
Rest before flipping: Remove the pan from the oven and let it rest for 10 minutes so the caramel glaze sets slightly before unmolding.
Flip and serve: Place a serving plate over the pan and carefully invert it, letting the bread and glaze release. Let the warm pieces drip and cool slightly, then pull apart by hand to serve.