Preheat oven to 350F and grease the muffin pan with coconut oil.
Sift together coconut flour, tapioca flour, cream of tartar, baking soda & salt to form the dry mixture.
Whisk together sweet potato puree, melted coconut oil, coconut milk, lemon juice and honey to form the liquid mixture. The liquid should be think and not pasty. You may heat the liquid for about 10 seconds to get it runny.
Using the wisk attachment on a stand mixer, whip the eggs on high speed until very foamy and pillowey (about 5 mins).
Slowly pour in liquid mixture while whipping. Turn off the mixer after all the liquid is poured. It should still be fluffy.
Sprinkle the dry mixture over the whipped fluff and gently stir with a whisk without whisking. Give a couple of folds with a spatula until incorporated. Careful not to overmix.
Evenly distribute into muffin pan, about 1/2 cup of batter for a 6-cup pan or 1/4 cup for a standard muffin tin.
Bake at 350F for 25-30 minutes.
Slice each bun in half and enjoy as a sandwich or shortcake.
Note: The honey makes the buns moist. It is recommended wrapping in a paper towel and may be kept at room temp a few days or longer in the 'fridge.