Ingredients

1 1/4 cups whole hazelnuts 

1 cup (2 sticks) unsalted butter 

2/3 cup granulated sugar 

2 large eggs 

1 teaspoon pure vanilla extract 

2 cups all-purpose flour 

1 teaspoon baking powder 

1 teaspoon ground cinnamon 

1/4 teaspoon salt 

1 teaspoon lemon zest 

Confectioners' sugar, for dusting 

1 cup seedless raspberry jam 

Preparation

Heat oven to 375 degrees. Toast hazelnuts until skins darken and begin to split, about 15 minutes. Transfer to a clean dish towel, and rub vigorously to remove skins; discard skins. Place nuts in a food processor; pulse until medium fine.

Line two baking sheets with parchment paper; set aside. In the bowl of an electric mixer, beat butter and granulated sugar at medium-high speed until light and creamy, about 2 minutes. Add eggs; beat until smooth, about 3 minutes. Beat in vanilla.

In a large bowl, combine flour, hazelnuts, baking powder, cinnamon, salt, and zest. Add to butter mixture; beat to combine, about 1 minute. Place in freezer until very firm, about 30 minutes.

Liberally dust a clean surface with flour, and roll out dough to 1/8-inch thickness. Using a 3-inch heart-shaped cookie cutter, cut out seventy-two hearts. To make top halves of cookies, use a 1-inch heart-shaped cookie cutter to cut out centers from thirty-six of the hearts.

Transfer cookies to prepared baking sheets, and bake until golden brown, about 8 minutes. Transfer to a wire rack until completely cooled.

Lightly sift confectioners’ sugar over cookie tops. Spread about 1 teaspoon jam on each of the bottom halves, and sandwich both halves together. Store in an airtight container for up to 1 week.