Step 1: Preheat your oven to 350°F (175°C) and grease or line an 8x8 inch square baking pan with parchment paper, leaving an overhang for easy removal.
Step 2: In a small saucepan, melt the butter over medium heat. Continue cooking, swirling the pan occasionally, until the butter foams and then turns a nutty golden brown. Remove from heat and let cool for 10 minutes.
Step 3: In a large mixing bowl, combine the browned butter and brown sugar. Whisk together until smooth and well combined.
Step 4: Add the egg and vanilla extract to the butter mixture, whisking vigorously for about 1-2 minutes until the batter looks glossy and slightly thickened.
Step 5: In a separate small bowl, whisk together the all-purpose flour, baking powder, salt, and cinnamon.
Step 6: Gently fold the dry ingredients into the wet ingredients using a spatula until just combined. Do not over-mix.
Step 7: Carefully fold in the diced pears and toasted walnuts until they are evenly distributed throughout the batter.
Step 8: Spread the batter evenly into the prepared baking pan. The batter will be quite thick, so use an offset spatula to smooth the top.
Step 9: Bake for 30-35 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out with a few moist crumbs.
Step 10: Allow the pear and walnut blondies to cool completely in the pan before lifting them out and slicing into squares.