You see it all the time in stores "Scottish" Short Bread, and it's most popular at the Holidays. What do the Scots know that makes their shortbread so special (and more expensive)? It's just a cookie, after all, a slightly sweet buttery cookie. How can something so plain be so fancy?
The answer is the flour. Authentic Scottish shortbread is made with at lead a quarter rice flour, some recipes call for all the flour to be rice, and that would be the most "authentic." Rice flour has no gluten, which aside from the benefit of appealing to the gluten free crowd, means the the dough bakes flakier and lighter. Gluten, when mixed with wet ingredients is what makes dough stiffen, and be less flaky. In hearty cookies like chocolate chip, this is a good thing, but in shortbread, where the flavor is subtle and mild, the rice flour lets the buttery taste shine through more vividly.
The following recipe will work made with any ratio of rice flour and all purpose flour, the below is just a suggestion.
1 cup unsalted butter
3/4 cup confectioner's sugar
1/2 teaspoon vanilla or almond extract
2 1/4 cups all purpose or pastry flour
1/4 cup rice flour
1/4 teaspoon salt
Beat butter until soft. Add sugar and extract. Beat until smooth. Stir salt into flour and mix well, then add flour and salt mixture to first mixture.
Press dough evenly into a round cake pan. Score into wedges (or petticoat tails) with a fork. Do not cut straight through the dough - score only 3/4 way through. Decorate lightly with patterns and frills if desired.
Bake in 375-degree oven 25 minutes. Cut along markings while still hot. Cool in pan, then turn out and sprinkle with a light dusting of confectioner's sugar if serving right away, or store in an airtight tin.