Lemon Meringue Sandwich Cookies

Granulated sugar 

Confectioners’ sugar 

table salt 

Large egg whites, at room temperature 

Cream of tartar 

Pure vanilla extract 

Vanilla bean paste

Unsalted butter 

Granulated sugar

Freshly squeezed lemon juice

Vanilla bean paste

Vanilla extract

Finely grated lemon zest

Large pinch of table salt

Large egg yolks