[header] How to make thumbprint cookies [title] Place the butter, sugar and vanilla extract in a large mixing bowl. [step] Beat the ingredients together with a handheld mixer or a stand mixer with a paddle attachment, mixing on medium speed for about 2 minutes. [title] Pour the flour and salt into a sifter or a sieve. 
[step] Either crank the sifter over a second mixing bowl or tap the sieve so that the flour and salt sift through the mesh and into the bowl. [title] Add 1 cup of the sifted dry ingredients into the butter mixer, mixing on low speed until just combined.