Prepare the Pan: Preheat the oven to 350°F. Lightly coat an 8-inch square baking pan with cooking spray, then line it with parchment paper, leaving some overhang on the sides for easy removal.
Cooking spray
Mix the Brownie Wet Ingredients: Add the melted butter, 1 cup sugar, and 1 teaspoon vanilla to a large mixing bowl. Beat until combined. Add 2 eggs and continue mixing until the mixture looks smooth, lighter in color, and slightly fluffy.
¾ cup unsalted butter, 1 cup granulated sugar, 1 teaspoon vanilla extract, 2 large eggs
Combine the Brownie Dry Ingredients: In a separate bowl, whisk together ½ cup flour, cocoa powder, salt, and 2 teaspoons cinnamon. Gradually add the dry ingredients to the butter mixture and mix only until no dry streaks remain. Do not overmix.
½ cup all-purpose flour, ½ cup unsweetened cocoa powder, ¼ teaspoon salt, 2 teaspoons ground cinnamon
Make the Pumpkin Cheesecake Batter: In a clean mixing bowl, beat the softened cream cheese until completely smooth. Add 1 egg, ⅓ cup sugar, ¼ cup flour, pumpkin puree, 1 teaspoon vanilla, ½ teaspoon cinnamon, and pumpkin pie spice. Beat until evenly combined and creamy, scraping down the sides of the bowl as needed.
8 ounces full-fat cream cheese, 1 large egg, ⅓ cup granulated sugar, ¼ cup all-purpose flour, ½ cup canned pumpkin puree, 1 teaspoon vanilla extract, ½ teaspoon ground cinnamon, 1 teaspoon pumpkin pie spice
Add the Brownie Base: Spread about two-thirds of the chocolate brownie batter evenly across the bottom of the prepared pan.
Add the Cheesecake Layer: Spoon the pumpkin cheesecake batter over the brownie base. Gently spread it into an even layer without mixing it into the chocolate batter underneath.
Create the Swirl: Drop spoonfuls of the remaining brownie batter over the pumpkin cheesecake layer. Drag a butter knife or wooden skewer through the top two batters in a loose back-and-forth pattern. Avoid scraping deeply into the bottom brownie layer if you want the layers to remain distinct.
Bake the Brownies: Bake for 40 to 50 minutes. The brownies are ready when the center looks set and a toothpick inserted near the center comes out with moist crumbs rather than wet batter. Avoid overbaking, since the brownies will continue to firm as they cool.
Cool Completely: Place the pan on a wire cooling rack and let the brownies cool completely in the pan.
Chill the Brownies: Refrigerate the cooled brownies for at least 1 hour before cutting. Chilling helps set the cheesecake layer and produces cleaner slices.
Slice and Serve: Use the parchment paper overhang to lift the brownies from the pan. Cut into 16 squares and serve chilled or allow them to sit briefly at room temperature before serving.