Mix the dry ingredients, cutting in the butter in small chunks. Blend in a food processor or crumble with your fingers until the butter is in pea sized chunks.

Whisk all the wet ingredients together. (Yup, including the vinegar! What you're making is low carb buttermilk!)

Add about 3/4 of the wet mix to the dry and mix with a spatula, adding the remaining 1/4 if its too dry. I used about 4/5 of a cup.

Fold in the frozen blueberries.

I just grabbed small handfuls and gently pressed the batter together, forming a ball. I got a dozen balls, flattening them slightly with a gentle push on the tops.

Bake for 17-22 minutes at 400F.