If you're a fan of cookies, you'll love these lemon curd thumbprint cookies. The buttery and crumbly cookies are filled with a tangy lemon curd center, creating a delightful contrast of flavors and textures. Start by creaming together butter, sugar, and vanilla extract. Gradually add flour until a dough forms. Roll the dough into small balls and make an indentation in the center of each cookie using your thumb. Bake the cookies until golden brown, then fill the indentations with lemon curd. Allow the cookies to cool before serving. These lemon curd thumbprint cookies are perfect for tea time or as a sweet treat any time of the day.