In a large mixing bowl, whisk 1 ¾ cup gluten-free flour blend, 1 tsp ground ginger, 1 tsp cinnamon, and ½ tsp sea salt.
Using a stand mixer or medium bowl, beat together ½ cup softened vegan butter and ¾ cup sugar until fluffy.
Add ¼ cup blackstrap molasses and ⅓ cup mashed banana, blending until smooth.
Slowly add the dry ingredients to the wet mixture. Mix until a sticky dough forms. Wrap the dough tightly with plastic wrap and chill in the fridge for 30 minutes.
Remove the gingerbread cookie dough from the fridge and roll it out on a lightly floured surface to ¼ inch thick. Use scraps to re-roll and cut shapes until all dough is used.
Transfer to Prepared Baking Sheets lined with parchment paper or cookie sheets. Chill again while preheating the oven to 350°F.
Bake for 12–14 minutes, or until slightly puffy. Cool on a cooling rack for at least 15 minutes before decorating.