I first glimpsed a version of these cookies on foodgawker, posted by Jamie (aka Sophistimom). There's nothing I love more than a simple shortbread cookie, especially one bursting with citrus flavor.
I tweaked the original recipe a bit and made them gluten-free by replacing the all-purpose flour with superfine brown rice flour. It worked like a dream. The finished cookies were delicious and you can't even tell the difference. The crumb is tight and crisp, just how a shortbread should be. I gave samples to two gluten-free friends and both gave the thumbs up.
Gluten-Free Lime Shortbread Sandwiches (adapted from Sophistimom)
12 tablespoons butter
1/2 cup confectioner’s sugarzest of 2 limes
1 tablespoon lime juice
1/2 teaspoon pure vanilla extract
1 1/4 cups superfine brown rice flour (I use Authentic Foods)
1/4 cup cornstarch
lime buttercream filling
Preheat the oven to 325 degrees. Line 2 baking sheets with parchment paper.
In the bowl of an electric mixer fitted with the paddle attachment, cream together butter, confectioner’s sugar, and lime zest until smooth. Add in lime juice and vanilla.
In a small bowl, combine salt, rice flour, and cornstarch. With the mixer on low, slowly add to the wet ingredients. Scrape down the bowl as necessary, and mix until well combined, but do not over mix.
Place dough in a pastry bag fitted with a large star tip and pipe small 1 inch rosettes onto the cookie sheets. Bake for 15 minutes, or until the edges just barely begin to brown. Allow to cool on a cooling rack. Match up cookies of similar sizes and sandwich together with a small amount of frosting.
Lime Buttercream Filling
2 tablespoons unsalted butter
1 1/4 cups confectioner’s sugar
1 tablespoon freshly squeezed lime juice
zest of 1 lime
Combine all ingredients and mix until smooth. Add more liquid or sugar as necessary to create the desired consistency.