Whisk together flour, sugar, baking powder, salt and baking soda.

Using a pastry cutter, cut in the chilled butter, until it looks like coarse meal, with some pea sized butter pieces remaining.

In a separate bowl, combine the sweet potato puree and buttermilk.

Then add the sweet potato/buttermilk mixture to the flour.

Stir with a fork, but don't over mix.

Then turn the dough out onto a floured surface, and knead into a ball. It is supposed to be lumpy - that's what makes them so buttery and crumbly!

Then flatten the ball into a disc shape, about 1 inch thick. The disc should be big enough to get 8 biscuits cut out of it.

Using a biscuit cutter or some other circle shape (like a cup), cut out 8 biscuits. Make sure to use all the dough.

In a preheated 425 degree oven, bake for 20-25 minutes, rotating the pan half way through baking.