Preheat oven to 400°F. Line a 12-cup muffin pan with liners or lightly grease it so nothing sticks later (because nobody wants to fight a muffin).

In a measuring cup, stir the oat milk and apple cider vinegar together. Set aside for about 5 minutes. It will thicken slightly, that’s exactly what you want.

In a large bowl, whisk together the flour, granulated sugar, brown sugar, baking powder, salt, and cornstarch. Break up any brown sugar clumps so the batter stays smooth and even.

Add the melted vegan butter and vanilla extract to the milk mixture. Whisk until fully combined.

Pour the wet mixture into the bowl of dry ingredients. Stir gently with a spatula until just combined. Stop as soon as you don’t see dry flour, overmixing makes dense muffins and we’re going for soft and fluffy.

Add the blueberries and gently fold them in so they’re evenly distributed. Try not to crush them, those juicy pockets are gold.

Scoop batter into the muffin pan, filling each cup about 3/4 full. A cookie scoop makes this super tidy and quick.

Bake for 20 minutes, or until the tops are lightly golden and a toothpick inserted in the center comes out clean (a little blueberry juice is fine).

Let muffins rest in the pan for 5 minutes, then move them to a rack to cool completely. Or at least long enough that you don’t burn your fingers, ask me how I know.