Hazelnut Sandwich Cookies

INGREDIENTS

• 2 1/2 cups all-purpose flour (spooned and leveled), plus more for rolling
• 3/4 cup granulated sugar
• 3/4 teaspoon baking powder
• 1/2 teaspoon fine salt
• 1/2 teaspoon cinnamon
• 1 cup hazelnuts, toasted and skinned
• 1 cup (2 sticks) unsalted butter, room temperature
• 2 large egg yolks
• 2 teaspoons pure vanilla extract
• Confectioners' sugar, for dusting
• 3/4 cup desired filling (see cook's note)