Preheat your oven to 375°F (190°C) and line your muffin tin with paper liners or lightly grease it. Gather all your ingredients and tools for an easy bake.
In a large bowl, whisk together the flour, sugar, and baking powder until well combined. This ensures even distribution of leavening and sweetness.
In a separate bowl, beat the eggs until slightly frothy, then add the softened butter and stir until the mixture is smooth and creamy. This creates a rich base for the batter.
Pour the wet mixture into the dry ingredients and gently fold with a spatula until just combined. Be careful not to overmix; a few lumps are fine.
Gently fold in the mixed berries, distributing them evenly throughout the batter without crushing them. If using frozen berries, add an extra minute to baking time.
Spoon the batter into the prepared muffin cups, filling each about two-thirds full. Sprinkle a little extra sugar on top for a crunchy finish if desired.
Bake the muffins in the preheated oven for 20-25 minutes, until they are golden on top and a toothpick inserted into the center comes out clean. The berries will be bubbling and juicy on the surface.
Remove the muffins from the oven and let them cool in the tin for about 5 minutes. Then transfer them to a wire rack or serve warm, enjoying the bright burst of berries with each tender bite.
