Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners or lightly grease it.
In a large mixing bowl, whisk together the sifted flour, granulated sugar, and baking powder until well combined. This creates an even, fluffy dry mixture.
In a separate bowl, melt the butter and let it cool slightly. Add the eggs one at a time, whisking after each addition until the mixture is smooth and slightly frothy. Stir in vanilla extract and lemon zest for a bright aroma.
Pour the wet mixture into the dry ingredients and gently fold with a spatula just until combined. Be careful not to overmix; the batter should be slightly lumpy but unified.
Gently fold in the frozen berries, taking care not to crush them to preserve their shape and color. The berries will stain the batter slightly, which adds to the rustic look.
Spoon the batter into the prepared muffin cups, filling each about ¾ full to allow room for rising. Sprinkle a little coarse sugar on top if desired for a subtle crunch.
Bake in the preheated oven for 20-25 minutes, or until the muffins are golden on top and a toothpick inserted into the center comes out clean. Your kitchen will fill with a sweet, fruity aroma.
Remove the muffins from the oven and let them cool in the tin for about 5 minutes. Then transfer them to a cooling rack and allow to cool for another 10 minutes, during which they firm up and develop a tender crumb.
Once cooled slightly, enjoy these moist, berry-studded muffins warm or at room temperature. They’re perfect for breakfast or a quick snack, with juicy bursts of fruit in every bite.
