In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large bowl, cream together the softened butter and granulated sugar until light and fluffy. Beat in the egg and vanilla extract until well combined.

Gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined; do not overmix.

Gently fold in your choice of fresh fruits into the batter.

Spoon the batter into prepared muffin cups, filling each about two-thirds full.

Bake in a preheated oven at 375°F (190°C) for 18-22 minutes, or until a toothpick inserted into the center comes out clean.

Let the muffins cool in the pan for a few minutes before transferring them to a wire rack to cool completely.