Preheat your oven to 325°F (163°C) and lightly grease a 9x5 inch loaf pan with a dab of butter or a spritz of cooking spray.
In a small saucepan, melt the butter over medium heat. Keep an eye on it as it foams and then begins to turn a golden brown. Remove it from the heat to prevent burning.
In a large mixing bowl, whisk together the mashed bananas, Greek yogurt, coconut sugar, eggs, almond milk, and vanilla extract. Pour in the cooled brown butter and stir until everything is well combined.
Time to introduce the whole wheat pastry flour, baking soda, and sea salt to the party. Gently fold them into the wet mix just until they're incorporated. If you're opting for chocolate chips, now's the moment to fold them in too. Be gentle to keep the bread tender.
Transfer the batter into your prepared loaf pan and smooth the top with a spatula. Slide it into the oven and bake for 50-60 minutes. It's done when a toothpick inserted into the center comes out mostly clean.
Let your banana bread cool in the pan for about 15 minutes before transferring it to a wire rack.