Preheat the oven to 350F.

Spray an 8x8 baking pan with baking spray and line the bottom with parchment paper. Set aside.

Make the BROWNIE BATTER first: In a small bowl, whisk together the melted butter, sugar, and vanilla until combined. Whisk in two eggs and beat mixture until thick.

In another small bowl, whisk together the flour, cocoa powder, baking powder, and salt.

Gradually add the dry ingredients into the wet, starting with a whisk to break up any clumps, then switching to a spatula to fold everything together until thoroughly combined. Set aside.

Next, make the PUMPKIN SWIRL BATTER: In a medium bowl, add one egg and whisk until broken up, then whisk in the pumpkin puree, oil, and sugar until all ingredients are combined.

In another medium bowl, whisk together the flour, baking soda, salt, cinnamon, nutmeg, cloves, and ginger.

Gradually add the dry ingredients into the wet, starting with a whisk to break up any clumps, then switching to a spatula to fold everything together until thoroughly combined. Set aside.

Take your prepared baking pan and scoop about half the brownie batter into the bottom of the pan. Smooth the batter into even layer. It's okay if the batter doesn't reach edge-to-edge.

Pour all of the pumpkin swirl batter over the brownie batter that's in the pan, then carefully smooth the pumpkin swirl batter into an even layer.

Dollop the remaining brownie batter over the pumpkin swirl batter.

Use a knife to swirl the two batters together to create a marbelized effect on top, but be careful not to mix the two batters completely together. Less is more here.

Bake the pumpkin swirl brownies in the oven at 350F for 50 minutes, or until a toothpick inserted into the center comes out clean.

Cool completely in the pan on a wire rack, then cut and serve.