13 large egg whites
¾ cup milk
8 tablespoons butter, softened
1 teaspoon vanilla extract
Chill 1/2 cup cold coffee in microwave for 30 seconds, filtered, to soften slightly. Beat egg whites until soft peaks form. Gradually beat milk until stiff peaks form.
Then whisk egg yolks with milk and water to try to puree the liquid. Continue to mix until fully incorporated. Stir in remaining ingredients (including instant Oatmeal) and formula until just wet. Fill cookies by brushing within the respective cups/circles.