Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners or lightly grease it with butter or oil.
In a large mixing bowl, whisk together the flour, brown sugar, and baking powder until evenly combined. This creates a light, airy base for your muffins.
In a separate bowl, beat the eggs until frothy and slightly pale, about 30 seconds. Then, add the yogurt and oil, and whisk until the mixture is smooth and well-blended.
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 okay.
If you're adding blueberries, lemon zest, or other mix-ins, gently fold them into the batter now, distributing evenly.
Spoon the batter into the prepared muffin cups, filling each about three-quarters full. This gives the muffins room to rise and develop a nice dome.
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 smell sweet and tangy as they bake.
Once baked, remove the muffins from the oven and let them cool in the tin for about 5 minutes to set their structure.
Transfer the muffins to a wire rack to cool completely, or enjoy warm straight from the oven. They should be moist, tender, and have a slight tang from the yogurt.
Serve the muffins plain, or with a smear of butter, honey, or jam for extra deliciousness. They’re perfect for breakfast, snack time, or as a cozy treat any time of day.
