01 - Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, ensuring an overhang for easy removal.
02 - Add flour, cocoa powder, cinnamon, baking powder, and salt to a medium bowl and whisk until evenly blended.
03 - In a large mixing bowl, whisk melted butter and sugar until combined. Add eggs individually, whisking after each addition. Stir in vanilla extract.
04 - Fold ricotta cheese into the wet mixture until smooth and fully incorporated.
05 - Add dry ingredients to wet ingredients and gently stir just until integrated; avoid overmixing.
06 - Fold toasted walnuts or pecans into the batter evenly.
07 - Pour batter into prepared pan and smooth the surface using a spatula.
08 - Bake for 32 to 36 minutes, or until a toothpick inserted in the center yields a few moist crumbs.
09 - Allow brownies to cool completely in the pan on a wire rack. Use parchment paper overhang to lift out and cut into squares.