Makes about 18 cookies
4 tablespoons butter, room temperature
⅓ cup sugar
1 egg yolk
1 tablespoon vanilla extract
⅔ cup all-purpose flour
¼ teaspoon salt
⅛ teaspoon baking powder
Heat oven to 300F.
Brown butter. Remove from heat and cool in freezer.
Stir brown butter and sugar together until smooth. Add egg yolk and vanilla then stir until smooth. Add flour, salt and baking powder, and stir just until combined.
Roll the dough into a log the diameter of a half dollar, and slice into ¼-inch thick coins. Arrange on a greased baking sheet ½-inch apart. Cover with another sheet pan and bake for 18 minutes or bake uncovered for 20 minutes until golden brown. If you’re into a more cakey wafer, while still warm, transfer to a storage container— to steam ever so slightly. Otherwise cool completely before noshing or storing… If you have the willpower, wait for tomorrow!!