10 tablespoons unsalted butter, at room temperature +1 tablespoon for pan
1 1/2 cups brown sugar
3 large eggs
2 tablespoons pure vanilla extract
2 tablespoons pure maple syrup
1 cup pecan pieces, divided
2 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon salt
1/2 teaspoon baking soda
8 ounces white chocolate, cut into chunks
For the Sauce-
1/3 cup pure maple syrup
6 tablespoons unsalted butter
1/4 cup heavy cream
1/2 cup pecan pieces
Make the Blondies-
Preheat oven to 350°F. Line a 9×13-inch baking pan with foil. Coat foil with 1 tablespoon of butter.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and brown sugar until light and fluffy, about 3 minutes. Add eggs, one at a time, then the vanilla and maple syrup. Mix until thoroughly combined.
Using a food processor or blender, pulse 1/2 cup of the pecan pieces a few times until nearly fine. (Do not over-blend or you will end up with pecan butter.)
In a large bowl, whisk together the fine pecan pieces, flour, baking powder, salt, and baking soda.
Add flour mixture to the butter mixture and mix just until combined. Fold in remaining 1/2 cup of pecan pieces, and the white chocolate chunks.
Spread into prepared pan and bake 25-30 minutes, until edges are golden.
Make the Maple Butter Sauce-
In a small saucepan, heat the maple syrup and butter over medium heat. Do not stir, just gently swirl the pan a few times. Simmer a few minutes until bubbling and slightly thickened. Add cream to the pan (do not stir), and continue cooking another few minutes until sauce comes together and gets syrupy and resembles caramel. Swirl the pan as needed to combine the ingredients.
Serve warm with vanilla ice cream and top with the Maple Butter Sauce and pecan pieces.