A step beyond drop cookies, these are the ultimate hands-on project.
• Coat hands with cooking spray before handling the dough to prevent it from sticking.
• Use a ruler or measuring spoons for the first few cookies to help you determine the right size; then you can judge the rest by eye.
• If the dough starts to stick to the bottom of the glass you use for flattening, coat the glass with cooking spray after every three or four cookies.
• To ensure thumbprint cookies hold their shape so they can be filled, chill the dough thoroughly after making the thumbprint indentations.
• Spoon filling into thumbprint cookies only after they've cooled completely.