Preheat your oven to 180°C (350°F) and prepare a muffin tin by greasing it or lining with paper liners.
In a large mixing bowl, whisk together the flour, baking powder, and salt until evenly combined. This creates a light, fluffy base for the muffins.
In a separate bowl, beat the eggs until they are frothy and slightly pale, then stir in the olive oil and milk until the mixture is smooth and well blended.
Finely chop the fresh spinach, then gently fold it into the wet ingredients along with the crumbled feta cheese. The spinach should wilt slightly and turn vibrant green as you fold it in, releasing a fresh aroma.
Pour the wet mixture into the bowl with the dry ingredients. Using a spatula, gently fold everything together until just combined. The batter should be a little lumpy but evenly mixed.
Divide the batter evenly among the muffin cups, filling each about three-quarters full. You should see the batter mound slightly over the top of each cup.
Bake in the preheated oven for 20–25 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean. Your kitchen will fill with a warm, cheesy aroma.
Remove the muffins from the oven and let them rest in the tin for about 5 minutes to set up. Then, transfer the muffins to a cooling rack and allow them to cool slightly, revealing a moist crumb with crispy edges.
Serve these muffins warm or at room temperature. The fluffy interior paired with the salty feta and tender spinach makes for a satisfying bite. Enjoy them as a quick breakfast or a savory snack any time of day!
