Preheat the oven to 400F (200C).

Bake the sweet potatoes for 50 minutes, or until they are soft.

Remove the sweet potatoes from the oven and let them cool.

Peel the cooled sweet potatoes and place the flesh into a large bowl.

Mash the sweet potatoes well until smooth.

Add the tapioca flour, coconut flour, egg, salt, baking soda, and garlic powder to the bowl.

Stir all the ingredients together until well combined.

Refrigerate the dough for 30 minutes to chill.

Dust a clean work surface with tapioca flour.

Take a handful of the chilled dough and roll it into a long, thin rope.

Cut the rope into 1-inch segments.

Use a fork to gently flatten each segment, creating ridges.

Prepare a large pot of water and bring it to a bare simmer.

Working in small batches, carefully drop the gnocchi into the simmering water.

Cook each batch for about 1 minute.

Once the gnocchi float to the top, remove them with a slotted spoon.

Place the cooked gnocchi into a colander to drain.

Melt the butter in a pan over medium heat until it turns light brown.

Add the sage to the melted butter.

Place the gnocchi into the pan with the butter and sage, and pan-fry them until lightly golden.