Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners or lightly grease it. Gather your ingredients and measure out the flour, sugar, baking powder, and salt into a large bowl. Whisk them together until evenly combined.
In a separate bowl, combine the creamy peanut butter, eggs, milk, and vanilla extract. Whisk until the mixture is smooth, creamy, and slightly frothy — this helps the peanut butter melt into the batter evenly.
Pour the wet mixture into the bowl with the dry ingredients. Gently fold everything together with a spatula or spoon until just combined. Be careful not to overmix; the batter should be a bit lumpy and thick but well incorporated.
Divide the batter evenly among the muffin cups, filling each about three-quarters full. Use a spoon or an ice cream scoop for neat, consistent portions. The batter should mound slightly over the top of each cup.
Bake the muffins in the preheated oven for 15-20 minutes. You'll notice the tops turning a warm, golden brown and possibly cracking slightly. Insert a toothpick into the center of a muffin; if it comes out clean, they're ready.
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 slightly. The smell of toasted peanut butter and baked batter will fill your kitchen — it’s irresistible!
Serve the muffins warm or at room temperature. For an extra touch, drizzle with honey or sprinkle a pinch of sea salt on top before serving. Enjoy their moist, tender crumb with a rich peanut aroma in every bite!
