Preheat your oven to 325°F and grease a Bundt pan or tube pan.
In a medium-sized bowl, whisk the flour, sugar, baking powder, cinnamon, and salt to combine.
In a large bowl, combine the mashed banana, eggs, milk, oil, and vanilla extract, whisking until well-combined.
Add the flour mixture to the wet ingredients, and mix until well-combined. There will be some lumps, but that is ok. Transfer the batter to the prepared baking pan.
Bake for 50 - 60 minutes, until a toothpick inserted into the cake comes out clean or with a few moist crumbs. Allow the cake to cool completely before decorating.
Once the cake is cooled, melt the white chocolate according to the package directions. Stir in half of the green food coloring and whisk to combine. If the color is not intense enough, add more food coloring as needed.
Place the cake on a wire rack or a rimmed baking sheet. Pour the melted, tinted white chocolate over the cake until coated. You can use the back of a spoon to press the chocolate into the sides of the cake if there are uneven places that the chocolate doesn’t fall into.
Sprinkle the cake with sugar hearts, if desired, and refrigerate until the chocolate is set.
Store this cake for 5 - 7 days in the refrigerator.