In a large mixing bowl, stir together the flour, baking powder, baking soda, salt, and erythritol (if you use a liquid sweetener, mix it with the wet ingredients in the next step).
Combine the milk and vinegar and let it sit for 3-5 minutes, allowing milk to curdle (that’s a simple method to make homemade buttermilk). Once the mixture curdled, add the eggs, melted butter, and vanilla and whisk together until well blended.
Add the wet ingredients to the dry ingredients, stirring until just combined.
Add the blueberries and gently fold in.
Heat a non-stick skillet or griddle on medium heat. Lightly brush with butter, ghee, or oil. Once hot, pour about 1/4 cup of the batter on the skillet. Cook on the first side until the edges look dry and the bottom is golden brown (about 2 minutes), then flip and cook on the second side for additional 1-2 minutes. Repeat with the remaining batter.
Serve warm with your favorite toppings and enjoy!