These lemon curd thumbprint cookies are a delightful twist on traditional thumbprint cookies. The cookie dough is made with butter, sugar, flour, and a hint of lemon zest for a subtle citrus flavor. Once the cookies are baked, they are filled with a dollop of tangy lemon curd. The combination of the buttery cookie and the tangy lemon curd creates a perfect balance of flavors. These cookies are perfect for holiday baking or as a sweet treat any time of the year.