For best results, use a kitchen scale to measure your ingredients accurately. Make sure the butter is at room temperature for the buttercream to achieve the right consistency. If the chocolate glaze becomes too thick, add a teaspoon of butter and microwave for another 10 seconds until smooth. Store the finished cookies in an airtight container in the refrigerator or freezer to maintain their freshness. Feel free to experiment with different types of chocolate for the glaze, such as milk chocolate or white chocolate.