In a large pot, heat 3 inches of canola oil to 350°F on a candy thermometer; track and adjust the heat to maintain the temperature. Line a sheet pan with parchment paper.
The amount of GF flour blend you need for these doughnut recipes may vary depending on the brand you use: Shannon uses Pillsbury Best Multi-Purpose Gluten Free Flour Blend, and we also like the results using Bob’s Red Mill Gluten Free 1-to-1 Baking Flour. (Cup4Cup didn’t work well.) If your dough is still too sticky to handle after mixing in all the dry ingredients, add more flour, 1 tablespoon at a time, until the dough is slightly tacky but easy to shape with your hands.