- 1 cup (2 sticks) unsalted butter
- 2/3 cup 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 grated lemon zest
- 1 1/4 cups hazelnuts, ground medium fine
- 1/2 cup seedless raspberry or cherry jam
Heat oven to 350 degrees. In the bowl of an electric mixer, beat butter and sugar at medium-high speed until light and creamy, about 2 minutes. Add eggs, and beat until smooth, about 3 minutes. Beat in vanilla.
Combine flour, baking powder, cinnamon, salt, and zest. Add to butter mixture; beat on medium speed until combined, about 1 minute. Refrigerate for at least 30 minutes.
Form dough into 3/4-inch balls, and roll in ground hazelnuts. Place balls on ungreased baking sheet 1 inch apart. Bake until cookies begin to set, about 8 minutes. Remove from oven. Working quickly, make a slight indentation in each cookie with your thumb. Return to oven, and bake about 8 minutes more. Place on a wire rack to cool.
Melt jam in a small saucepan over medium-low heat. Place 1/4 to 1/2 teaspoon of jam in each indentation. Cool completely.