INSTRUCTIONS

1. Arrange rack in center of oven. Preheat to 325°F. Generously butter a 9 x 9-inch metal baking pan. Line with parchment, overhanging edges on two opposite sides.
2. For the blondies, arrange pecans on a rimmed baking sheet. Bake in center of oven until very lightly toasted, about 5 to 7 minutes. Transfer to a rack and let it stand until cool enough to handle, about 5 minutes.
3. Meanwhile, stir flour with baking powder, salt, cinnamon, allspice, and nutmeg in a medium bowl. Set aside.
4. Whisk butter with sugars and vanilla seeds in a large bowl until smooth. Add eggs, whisking until mixture is fully smooth and combined. Using a spatula, fold in flour-mixture until no white streaks remain.
5. Roughly chop ½ cup of toasted pecans, then gently fold in along with chocolate, just until combined. Scrape batter into prepared pan, smoothing top with a small offset spatula or spoon. Sprinkle remaining pecans evenly overtop, then press down lightly to adhere.
6. Bake in the center of the oven until blondie has set, about 30 minutes (a toothpick inserted into the center should come out clean with moist crumbs attached). Transfer to a rack and let cool for 30 minutes.
7. For the glaze, stir icing sugar with milk and cinnamon in a small bowl until smooth (mixture will be thin). Using parchment edges, lift blondies out of the pan onto a rack. Brush icing evenly over blondies to fully cover. Let it stand until glaze is dry to the touch and blondies have cooled completely, about 30 more minutes.
8. With a sharp serrated knife, cut lengthwise into four rows, then crosswise into four rows to make 16 squares. Serve immediately.