Step 1: Preheat your oven to 350°F (175°C) and grease an 8x8 inch baking pan or line it with parchment paper for easy removal of the sweet potato and maple blondies.
Step 2: In a small saucepan over medium heat, melt the butter and continue cooking until it turns a golden brown color and smells nutty. Remove from heat and let it cool slightly.
Step 3: In a large bowl, whisk together the browned butter, roasted sweet potato puree, maple syrup, brown sugar, egg, and vanilla extract until the mixture is smooth and fully combined.
Step 4: In a separate bowl, sift together the flour, cinnamon, nutmeg, baking powder, and salt. Gradually add the dry ingredients to the sweet potato mixture.
Step 5: Gently fold the dry ingredients into the wet batter using a spatula until just combined. If using, fold in the chopped pecans now.
Step 6: Spread the batter evenly into the prepared baking pan. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs.
Step 7: Allow the sweet potato and maple blondies to cool completely in the pan before slicing into 16 squares.