Spicy Cinnamon-Chocolate Brownies

INGREDIENTS

• Vegetable oil cooking spray, for greasing pan
• 1 tablespoon ground cinnamon
• 1 stick unsalted butter, at room temperature, cut into 1/2-inch pieces
• 3 large eggs, at room temperature
• 1/2 teaspoon cayenne pepper
• 2 tablespoons unsweetened cocoa powder
• 1/2 cup vegetable oil
• 1 cup semisweet chocolate chips, such as Ghiradelli
• One 21-ounce box brownie mix, such as Duncan Hines Chewy Fudge
• Ground cinnamon, for dusting
• 1/2 cup heavy cream, at room temperature