Ingredients1 cup (2 sticks or 8 ounces) unsalted butter, at room temperature 1/2 cup sugar 2 large eggs, at room temperature 1 teaspoon vanilla extract 1/4 teaspoon salt 2 cups all-purpose flour 1 cup chopped nuts (optional) 3/4 cup jam, any kind https://www.simplyrecipes.com/recipes/thumbprint_cookies/