Preheat and prep: Preheat your oven to 375°F (190°C) and line a muffin tin with paper cups or grease lightly. This is the easiest part, and yes, it’s non-negotiable.

Mix dry ingredients: In a big bowl, whisk together flour, sugar, brown sugar, baking powder, baking soda, salt, and cinnamon. Try not to taste the raw flour…even though it’s tempting.

Mix wet ingredients: In another bowl, whisk milk, oil, egg, and vanilla until smooth and slightly dreamy.

Combine: Pour the wet into the dry and stir gently with a spatula. Do not overmix! Lumps are okay—seriously, they make muffins better.

Add berries: Fold in blueberries and raspberries carefully. Treat them gently—they’re delicate little rebels.

Fill muffin cups: Spoon the batter evenly into your muffin cups, about ¾ full. Sprinkle coarse sugar on top if you want that bakery sparkle.

Bake: Bake for 20–25 minutes, or until a toothpick comes out clean (don’t trust the muffin jiggle test—it’s trickier than it sounds).

Cool: Let them cool for 5–10 minutes in the pan, then transfer to a wire rack. Try not to eat them all hot out of the oven…or maybe don’t.