1 1/2 c. unsalted macadamia nuts, chopped
2 1/2 c. flour
3/4 c. sugar
2 tsp. grated lemon peel
1/2 tsp. salt
1 c. chilled unsalted butter, cut in pieces
1 egg
1 tsp. vanilla

Blend flour, sugar, lemon peel and salt in food processor. Add butter and process until coarse meal forms, using on/off turns. Add egg and vanilla and process until just blended. Transfer to bowl. Gently mix in nuts. Refrigerate at least 2 hours.

Preheat oven to 325°F. Lightly butter baking sheet (or use parchment paper). Let dough soften 10 minutes. Roll out on floured pastry cloth 1/4-inch thick. Cut into 2 1/2 to 3-inch hearts. Refrigerate cookies on cookie sheet 15 minutes before baking. Bake until edges begin to turn golden brown, about 18 minutes. Cool on rack.

Makes 3 to 4 dozen.