Preheat oven to 350°F. Lightly grease a donut baking pan.
In a large bowl, whisk together the rice flour, almond flour, coconut sugar, arrowroot, baking powder, cinnamon, and salt.
Slowly pour in the orange juice and whisk until well combined.
Add the oil, almond butter, vanilla extract, and orange zests if using. Whisk until everything is incorporated.
Spoon the batter into the donut pan, filling 3/4 of the cavities. If you have a piping bag, feel free to use it; it will be easier.
Bake for 15 minutes in the preheated oven. Let cool for at least 1 hour before trying to remove the donuts from the pan.
Salted Caramel Glaze
Combine all ingredients except the vanilla extract in a large saucepan.
Bring to a boil, whisking constantly for the first 2 minutes.
Let simmer for about 30 minutes, stirring every 8-10 minutes until the mixture has thickened and has a caramel color. It should have reduced in volume by about 50%
Remove from heat, stir in the vanilla extract, and let the glaze cool for about 10 minutes. If it's not thick enough, let simmer again for another 5-10 minutes.
Pour the glaze into a small bowl and dunk the donuts, letting the excess glaze drip off. Transfer to a wire rack and sprinkle with sea salt and funtettis.
Notes
Don't substitute white rice flour with brown rice flour. I tried, and the donuts had a slightly bitter aftertaste.I recommend you let the glaze cool for at least one hour to check if it's thick enough. If the consistency is really thick and not too sticky, just reheat gently before glazing the donuts. If it's not, bring it back to a boil and let simmer again until it's thicker.The recipe for the caramel glaze is adapted from Fork and Beans.