In a large mixing bowl, sift together the all-purpose flour, salt, baking powder, baking soda, ground cinnamon, ground nutmeg, and brown sugar. Whisk until thoroughly combined, ensuring there are no lumps.

In a separate bowl, mash the ripe bananas with a fork until smooth. Aim for a creamy consistency with few lumps.

Add the cold, cubed butter to the dry ingredients and use a pastry cutter or two forks to cut the butter until it resembles small peas.

Pour the mashed bananas into the dry mixture, followed by a lightly beaten egg, vanilla extract, and heavy cream. Mix gently using a spatula until just combined.

Transfer the dough onto a parchment-lined baking sheet and pat it into a round shape about 7 inches in diameter. Cut the dough into 8 equal triangles.

Place the scone dough in the freezer for 20 minutes to firm up. Preheat your oven to 375°F (190°C). Once chilled, brush the tops with heavy cream and sprinkle with granulated sugar. Bake for 25-28 minutes.

While the scones bake, prepare the cream cheese glaze by beating softened cream cheese until smooth, then gradually adding powdered sugar, milk, and vanilla extract.

Once the scones are out of the oven, let them cool for about 5 minutes, then drizzle the cream cheese glaze over the warm scones.