Ingredients

• 12 tbsp. unsalted butter, plus more for greasing pan
• ³⁄₄ cup flour
• ¹⁄₂ cup whole-wheat flour
• ¹⁄₂ cup hazelnuts, roasted, cooled, and finely ground in a food processor
• ¹⁄₂ tsp. kosher salt
• ¹⁄₂ cup sugar
• ¹⁄₄ cup turbinado sugar
• 1 egg
• ¹⁄₂ vanilla bean, seeds scraped and reserved
• ²⁄₃ cup raspberry preserves
• 1 tsp. orange zest

Instructions

1. Line a 9" square baking pan with parchment paper and grease; set aside. Whisk together both flours, hazelnuts, and salt in a bowl; set aside. In another bowl, beat butter and both sugars on medium speed of a hand mixer until pale and fluffy, about 5 minutes. Beat in egg and vanilla seeds. Add dry ingredients, and beat until just combined. Remove and reserve ½ cup dough; transfer remaining dough to prepared pan and press into bottom. Using an offset spatula, spread remaining dough into a 9" square on a sheet of parchment paper; refrigerate both doughs for 1 hour.
2. Heat oven to 350°. Stir together preserves and zest in a bowl, and then spread over dough in baking pan. Using a knife or pizza cutter, cut dough into 10 strips; lay 5 strips crosswise and then lay the remaining 5 strips lengthwise to form a grid over preserves. Bake until golden brown and preserves are bubbling, about 45–50 minutes. Let cool completely; unmold and cut into 36 squares.