Preheat your oven to 180°C (350°F). Lightly grease your muffin tin or line it with paper liners to prevent sticking.
In a large mixing bowl, whisk together the flour, sugar, and baking powder until evenly combined. This creates a fluffy, uniform base for your muffins.
Add the creamy peanut butter to the bowl and stir it into the dry mixture until it looks slightly streaked but still crumbly.
Pour in the milk and vegetable oil, then crack in the eggs. Use a whisk or spoon to gently fold all the ingredients together until just combined—don’t overmix, or the muffins may turn dense.
Once the batter looks thick but smooth, divide it evenly among the muffin cups, filling each about three-quarters full—use a spoon or scoop for clean, even portions.
Bake in the preheated oven for 20 to 22 minutes, or until the tops turn a light golden brown and a toothpick inserted in the center comes out clean. You’ll hear a gentle sizzle as the muffins bake and see their edges firming up.
Remove the muffins from the oven and let them rest in the tin for about 5 minutes. Then, transfer them to a wire rack to cool completely—this prevents sogginess and allows the aroma to fully develop.
Once cooled, serve the muffins warm or at room temperature. For an extra touch, sprinkle a pinch of sea salt on top or drizzle with honey while they’re still warm for added flavor.