In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the eggs one at a time, then add the vanilla extract.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually mix the dry ingredients into the wet mixture, then stir in the mashed banana until fully combined.
Cover the dough and refrigerate for at least 1 hour until firm.
Roll the chilled dough into 1-inch balls and place them on a baking sheet lined with parchment paper.
Freeze the truffles for 30 minutes until solid.
While the truffles freeze, prepare a white chocolate ganache. Melt white chocolate with a bit of coconut milk (or dairy milk if acceptable) and stir until smooth.
Once truffles are frozen, dip each ball into the ganache, allowing excess to drip off.
Place the coated truffles on a wire rack to set at room temperature.
Store in an airtight container in the refrigerator until ready to serve.