Step 1

Preheat oven to 300F.

Step 2

Cream together softened butter and sugar for about 2 minutes in a stand mixer until just smooth.  Scrape down the sides.

Step 3

Add vanilla.  Mix another few seconds to incorporate.

Step 4

Add all-purpose flour, rice flour and salt.  Add any flavorings at this time (see notes).  Mix on medium speed just until the dough comes together, and starts to pull away from the bowl.  Scrape the dough out and pat it into a flattened square.

Step 5

Roll as evenly as you can to 1/2″ thickness.

Step 6

Trim the edges (if you want them even) and cut into approximately 1 x 3-inch strips.

Step 7

Carefully space out on a sheet pan, easiest to use a metal spatula for this.  Chill the entire tray of cookies for 15 minutes in the refrigerator, or place in the freezer for 5 minutes.

Step 8

Place the cold tray of cookies in the oven.  Bake for 30 minutes.  Let rest on the tray a few minutes and move to a cooling rack.  They will crisp up as they cool.