Lightly coat an 8 × 4-inch loaf pan with nonstick spray.
Blend the chestnuts in a food processor until finely ground.
Add the bananas, vanilla, oil, milk, applesauce, and sugar.
Process until mostly smooth (it’s okay if small banana pieces remain).
In a large-size bowl, whisk together the brown rice flour, whole wheat pastry flour, arrowroot powder, baking powder, baking soda, and salt.
Fold the wet ingredients into the dry ingredients carefully, being cautious not to overmix.
Fold in the white chocolate chips.
Pour the batter into the prepared loaf pan.
Bake for 60 minutes, or until a toothpick inserted into the center comes out clean.
Let cool for 15 minutes in the pan before transferring the bread to a wire rack to cool completely.
Notes / Tips / Wine Advice:
Serving Tip:Serve warm with a light spread of nondairy butter or enjoy as is for a cozy snack or breakfast.Wine Advice:Pair with a sweet dessert wine such as a Moscato or a mild white wine to enhance the marzipan-like flavor.