Preheat the oven to 350°F. Generously grease a bundt pan.

Combine the granulated sugar and 1 tablespoon cinnamon in a large mixing bowl or zip-top bag.

Cut each biscuit into quarters and toss the pieces in the cinnamon sugar until coated.

Arrange half of the coated biscuit pieces in the prepared bundt pan.

Stir together the melted butter and 3/4 cup brown sugar, then spoon about half over the biscuit layer.

Add the remaining biscuit pieces to the pan and pour the rest of the butter-brown sugar mixture over the top.

Bake for 35 to 40 minutes, until deep golden brown and set in the center. Tent loosely with foil near the end if needed to prevent over-browning.

While the bread bakes, melt 1 tablespoon butter in a small skillet over medium heat. Add the diced apples, 2 tablespoons brown sugar, and 1/2 teaspoon cinnamon.

Cook for 5 to 7 minutes, stirring occasionally, until the apples are tender and the sauce is glossy. Stir in the vanilla extract and remove from the heat.

Cool the monkey bread in the pan for 10 minutes, then carefully invert onto a serving plate.

Spoon the warm apple topping over the monkey bread and serve warm.