Preheat the oven to 425 degrees and line a 12-count muffin pan with tulip liners.
In a liquid measuring cup, combine the almond milk, vinegar, and chia seeds. Set it aside.
Whisk the flour, sugars, baking powder, and salt. Gently mix in the blueberries with a rubber spatula.
Whisk the olive oil, melted butter, sour cream, apple sauce, vanilla, and chia egg in another large bowl.
Gently mix the wet ingredients into the dry ingredients with a rubber spatula until combined.
Use a cookie scoop to evenly distribute the batter between the wells of the muffin pan. Top with more fresh blueberries if you like.
Bake the muffins for 22 to 27 minutes until a toothpick inserted into the center comes out clean.
Cool the muffins in the pan for 10 minutes. Then, transfer them to a wire cooling rack to cool completely. Enjoy!
Notes
Storage
Store these muffins in an airtight container for up to 3 days on the counter.
These muffins will also last for up to 5 days in the refrigerator in an airtight container.
For longer storage, wrap the muffins in plastic wrap and freeze them for up to 3 months in an airtight, freezer-safe container.
Bring the muffins to room temperature on the counter before serving.
General Tips
I recommend measuring your flour by weight if possible. Check the label on your container, as different gluten free flours weigh different amounts.
If you don't have a food scale, loosely spoon your flour into your measuring cup and level it off with a knife. NEVER scoop flour out directly with your measuring cup. It will compact, and you'll use too much.
Make sure your baking powder is fresh. Stale baking powder won't give the muffins that nice, crowned top.