Preheat the oven to 350 degrees. Line a muffin tin with cupcake liners.
In a large bowl combine the flour, sugar, cornstarch, baking powder, cinnamon, nutmeg, salt, and cardamom. Mix to combine.
Stir in the oat milk, vegetable oil, vanilla, and vinegar. Mix until well combined. Allow the batter to rest for 5 minutes then gently fold in the peaches.
Use a large cookie scoop and scoop the butter into each muffin cup filling it 3/4 of the way full. Bake for 22-25 minutes.
Remove from oven and allow to cool for 5 minutes in the pan before transferring to a wire rack to cool completely.
Notes
Adapted from Bake and Destroy: Good Food for Bad Vegans by Natalie Slater