Preheat your oven to 350°F (175°C) and prepare a cake pan by greasing it lightly or lining it with parchment paper.

In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the eggs one at a time, mixing until smooth.

In a separate bowl, whisk together the flour, baking soda, salt, and cinnamon.

Mash the bananas and fold them into the wet mixture until thoroughly combined.

Gradually add the dry ingredients to the banana batter, folding gently until just combined. If using, fold in the nuts.

Pour the batter into the prepared cake pan and smooth the top. Bake for 30-35 minutes or until a toothpick comes out clean.

Allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.