1 ⅓ cupsraw sugar or sugarplus two additional teaspoons
3eggslarge, at room temperature
2tsppure vanilla extract
1 ¼cups/140 g gluten-free oat flour
½cup/60 gsweet white rice flour
¼cupcornmealfinely ground
2 ½tspbaking powder
¼tspfine sea salt
⅛ + 1tspground cinnamon
½cupbuttermilkat room temperature
Instructions
Preheat oven to 375° F. Butter an 8 x 8 square pan.
In a large bowl using an electric mixer on medium speed, cream the butter and sugar until it is light and fluffy, about 2-3 minutes. Add the eggs one at a time, beating well after each addition. Beat in the vanilla extract.
In a medium bowl, sift together the flours, baking powder, salt, and 1/8 teaspoon cinnamon.
Add the flour mixture and the buttermilk to the butter/etc., in three additions, starting with 1/2 cup of flour and 1/3 of the milk, and ending with the remaining flour. Stir well after each addition.
Spoon the batter into the cake pan, and smooth the top with a spatula. Sprinkle the 2 additional tablespoons of sugar and the 1 teaspoon cinnamon evenly across the top. Place pan in oven and bake about 30 minutes or until a toothpick inserted in the cake comes out clean. Remove from oven and cool in pan 15 minutes, then turn out onto a rack to cool completely.