Banana Muffins with Pecans

Ingredients

• 1 (5 oz or 150 g) ripe banana, mashed
• 1/2 stick (2 oz or 60 g) salted butter, at room temperature
• 3 tablespoons (1.8 oz or 45 g) granulated sugar
• 1 (2 oz or 60 g) whole egg
• 1/4 teaspoon (1.5 ml) vanilla extract
• 3/4 cup (3.2 oz or 90 g) all-purpose flour, sifted
• 1/4 teaspoon (1.5 g) baking powder