Preheat your oven to 350 degrees F. Spray a 9-inch square baking pan with pan spray, line with parchment and spray the parchment. Set aside.
Place the diced apples in a single layer on a microwave-safe plate and cover with another plate. Microwave for 2 minutes, until the apples have softened and given off some liquid. Transfer the apples to a paper towel-lined tray and set aside.
In a medium saucepan over medium-high heat, brown the butter until it is a deep golden color, 5 to 7 minutes. Immediately pour the hot butter into a medium heat-proof mixing bowl. Add the cinnamon, clove, salt, baking powder and brown sugar. Whisk to combine. Whisk in the vanilla, whole egg and egg yolk until smooth. Add the all-purpose flour and stir with a rubber spatula until nearly combined. Add the reserved apple pieces and the nuts to the batter, saving about 2 tablespoons of each for topping the blondies. Stir the batter until the nuts and apples are evenly combined and then pour the batter into your prepared pan. Press the reserved pecans and apple pieces evenly into the top of the batter.
Bake the blondies until golden and a toothpick insert near the center comes out with a few moist crumbs, 33 to 35 minutes. Allow to cool in the pan before cutting with a serrated knife into 16 bars.
Microwaving the apples par-cooks them and prevents shrinking while the apples bake in the blondies. Adding the spices to the hot brown butter "blooms" them, thereby waking up their flavor.