Preheat the oven to 375°F (190°C) and grease the muffin tin.

In a mixing bowl, whisk together the dry ingredients: flour, sugar, baking powder, and salt.

In another bowl, combine the wet ingredients: milk, vegetable oil, egg, and vanilla extract.

Pour the wet ingredients into the dry ingredients and mix until just combined.

Gently fold in the raspberries.

Spoon the batter into the prepared muffin tin, filling each cup about ⅔ full.

Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean.

Allow the muffins to cool in the tin for 5 minutes before transferring to a wire rack.