Preheat your oven to 180°C (350°F). Line a muffin tin with paper liners or lightly grease it to prevent sticking.
In a large mixing bowl, combine the peanut butter and sugar. Use a whisk or spoon to stir until the mixture is smooth, creamy, and slightly fluffy, with a fragrant nutty aroma filling the air.
Add the beaten eggs to the peanut butter mixture and whisk until fully incorporated, creating a sticky, glossy batter.
Sprinkle in the baking soda and gently fold it into the batter to evenly distribute, which will help the muffins rise nicely.
Gradually add the flour, folding it in with a spatula or spoon just until the mixture is combined. Be careful not to overmix — the batter will be thick and slightly sticky.
Using a spoon or an ice cream scoop, divide the batter evenly among the muffin cups, filling each about 3/4 full. The batter should mound slightly above the top of the liner.
Bake in the preheated oven for 15-18 minutes, or until the muffins are golden on top and a toothpick inserted into the center comes out clean. The aroma of toasted peanut butter will waft through your kitchen as they bake.
Remove the muffins from the oven and let them cool in the pan for about 5 minutes. Then, transfer them to a cooling rack to cool completely or enjoy warm for a gooey, comforting treat.
Once cooled slightly, serve these muffins with a glass of milk or your favorite coffee for a satisfying snack or breakfast.