• Preheat the oven to 400°F (200°C). Line the muffin tin with paper liners.

Make the Muffin Batter

• Melt the butter over medium low heat and cool until it is barely warm, about 90°F (32°C). Crack the eggs into a small bowl.
• Place the all-purpose flour, baking soda, and salt in a bowl and whisk for 30 seconds to combine.
• Place the sugar, brown sugar, cinnamon, nutmeg and ginger in a large bowl. Use your fingers to break up any brown sugar clumps. Add the eggs and vanilla. Whisk for 1 minute until the mixture is creamy and lighter in color.
• Place the bananas in a medium sized bowl and use a fork or potato smasher to mash them up. Then use a whisk to make them creamy. Add the bananas to the batter and mix until fully incorporated.
• Add the melted butter and whisk until thoroughly mixed. Next whisk in the sour cream and let the batter sit for 5 minutes.
• Add 1/2 of the dry ingredients to the batter and fold it with a silicone spatula until incorporated. Add the remaining dry ingredients and mix just until all the flour is mixed in. Scrape the bottom to ensure you didn't miss any flour. The batter should be lumpy. Be careful not to overmix.

Bake the Muffins

• Divide the batter evenly between the 12 muffin cups. Bake the muffins at 400°F for 5 minutes and then without opening the oven door reduce the temperature to 350°F (180°C). Bake the muffins for another 15-17 minutes until the internal temperature registers at 195-200°F using an instant-read thermometer or a toothpick inserted in the top of the muffin comes out clean.
• Cool the muffins in the pan for 5 minutes, then move the muffins to a wire cooling rack.

Store the Muffins

• The muffins can be stored at room temperature in an airtight container for up to 3 days. Store They can be stored in an airtight container for up to 7 days. Bring them to room temperature before eating, or warm slightly in the microwave for 10-15 seconds.