• Preheat oven to 350°F. Grease and line a 9x9-inch square baking pan with parchment paper, ensuring it is long enough to extend over the sides of the pan to act as pull handles.

Make the streusel:

• In a small bowl, combine ½ cup flour, chopped pecans, brown sugar, and melted butter. Stir until it starts to form clumps. Set aside.

Make the blondies:

• In a medium-sized mixing bowl, whisk together 2 ½ cups flour, pumpkin spice, and salt. Set aside.
• Blot the pumpkin dry by spreading it on several layers of paper towel. Cover the pumpkin with additional paper towels and press out the excess liquid. You should end up with 2/3 cup of pumpkin; it will have a paste-like texture. Place the pumpkin into a small bowl and set it aside. This step is important as it keeps your blondies dense, not cakey.
• In a large heatproof bowl, melt 90g white chocolate and ¾ cup of butter in 30-second increments in the microwave, stirring after each increment, until smooth. Cool for 5 minutes.
• Whisk in the granulated sugar, egg yolks, and pumpkin until the mixture is smooth.
• Stir in the flour mixture, being careful not to overmix the batter!
• Cut the remaining white chocolate into chunks and fold those into the batter.
• Transfer the batter to the prepared baking pan, (the batter will be thick). Smooth the top before sprinkling with pecan streusel.
• Bake for 25-30 minutes or until the edges are golden and the middle is set. Check for doneness by inserting a toothpick into the center. If it comes out wet, continue to bake for 5 minutes or more. Recheck with the toothpick until it comes out clean, leaving only a few crumbs.
• Leave the brownies in the pan and allow them to cool in the refrigerator for 30 minutes. (This quick chill helps them slice cleanly). Gently lift the blondies from the baking pan using the parchment paper 'handles' and cut into 16 squares.