Preheat the oven to 350˚F (180˚C). Line a baking sheet with parchment or a silicone mat.
Cream the fats and sugar: In a medium bowl, beat 1/4 cup shortening, 1/4 cup butter, and 1/4 cup brown sugar until light and fluffy. Add 1 egg yolk and 1/2 teaspoon vanilla extract. Mix until smooth.
Add dry ingredients: Stir in 1 cup all-purpose flour and 1/4 teaspoon salt until a dough forms.
Shape and coat: Roll dough into small balls (about 2 teaspoons each). Beat the egg white lightly. Dip each ball into the egg white, then roll in 3/4 cup pecans, finely chopped.
Bake and indent: Place balls 1 inch apart on the baking sheet. Bake for 3 minutes. Remove from oven and gently press a small indentation into each center using your thumb or a cork. Return to the oven for 10–12 minutes, until lightly golden.
Repress and cool: Immediately after baking, gently repress the center if needed. Let cookies cool completely on a rack.
Make the icing: Mix 1 cup powdered sugar, 1/2 tablespoon butter, and 1-2 tablespoons milk until smooth and thick. Add a drop of food coloring if desired and swirl gently—don’t stir.
Fill the cookies: Spoon or pipe icing into the center of each cooled cookie. Let set before storing.
Notes
Nut-Free Option: Skip the pecans and roll the dough balls in coarse sugar—or leave them plain.Storage: Store in an airtight container at room temperature up to 5 days. Freeze unfilled cookies up to 2 months.
Cracks in your baked cookies? Cracking can happen if the dough is too cold or dry. A few cracks are normal—and pecans hide them well.