If oat flour alone didn't work well for your gluten-free shortbread cookies, there are several alternative flours or flour blends you can try. Here are a few options:
Almond Flour: Almond flour is a popular choice for gluten-free baking. It has a slightly nutty flavor and a finer texture that can work well in shortbread cookies. It's important to note that almond flour can make cookies more delicate, so you may need to adjust the recipe accordingly.
Rice Flour: Rice flour, particularly white rice flour, can be a good substitute for wheat flour in shortbread cookies. It has a mild flavor and a fine texture. You can use white rice flour alone or combine it with other gluten-free flours for better results.
Tapioca Flour: Tapioca flour, also known as tapioca starch, is a starchy flour made from cassava root. It adds a light and crisp texture to baked goods and can be used in combination with other gluten-free flours. However, using tapioca flour alone may result in a chewier texture, so consider combining it with other flours.
Gluten-Free Flour Blends: You can also try using pre-made gluten-free flour blends specifically designed for baking. These blends usually consist of a mix of various gluten-free flours and starches to mimic the texture and properties of wheat flour. Look for blends labeled specifically for cookies or shortbread to get the best results.
Remember that gluten-free baking can be a bit trial and error, and different flours can yield slightly different results. It's a good idea to experiment with different ratios and combinations of flours until you find the texture and taste you prefer for your shortbread cookies.