In a mixer, beat butter and sugar until well combined, about 2 minutes.
Add in 2 eggs and 2 egg yolks and mix until combined.
Add in vanilla and almond extract; mix until combined.
In a separate bowl, sift together flour, salt, and baking powder. Slowly (about a cup at a time) add flour to butter mixture and combine.
Mix ingredients until they are combined, if you over-mix this dough it can get tough.
Put dough in some Saran wrap and refrigerate for at least one hour, up to overnight.
When you are ready to bake, heat oven to 350 degrees. Roll dough out (this can take some time as the dough is stiff), cut out cookies, and bake for 6-8 minutes. Some readers have also suggested chilling the cut out cookie dough before baking.