Prepare oven and baking sheet: Preheat oven to 425 F degrees. Line a baking sheet with parchment paper.
Combine the dry ingredients: In a large mixing bowl, whisk together the flour, oats, sugar, baking powder, cinnamon, ginger, and salt. Add the butter straight out of the fridge so it’s nice and cold. You can cube it to make mixing easier. Using a pastry cutter or twi knives, cut the butter into the dry ingredients until it forms pea-sized pieces.
Combine the wet ingredients: Mash the bananas using either a fork or a potato masher in a mixing bowl. Add the 1/4 cup of milk, coffee, maple syrup, and vanilla. Mix well.
Finish the dough: Pour the wet ingredients into the large bowl of dry ingredients. Gently fold everything together using a spatula. Once a shaggy dough forms, use your hands to finish mixing and create a ball. Dump it out onto a lightly floured surface and sprinkle a little bit of flour over the ball. Knead it gently and roll it out unto a circle about 1 inch thick.
Finish the scones: Use a pastry cutter or knife to cut the dough into 8 equal sized wedges. Transfer the scones to the prepared baking sheet and brush them with milk.
Bake: Bake until lightly browned, about 15 to 18 minutes. Transfer scones to wire rack to cool slightly before serving.
Make the glaze: While the scones are baking, you can prepare your glaze. Mix the ingredients together and drizzle the glaze over the scones once they’ve fully cooled.