01 -  Combine root beer and brown sugar in a small saucepan over medium-high heat. Bring to a boil, then reduce to a gentle simmer. Cook until the mixture is thickened and reduced by half, about 10 to 12 minutes. Set aside to cool slightly. 
 02 -  In a large mixing bowl, whisk together flour, granulated sugar, baking powder, baking soda, and salt until fully blended. 
 03 -  In a separate bowl, beat together the egg, root beer, whole milk, melted unsalted butter, and vanilla extract until homogenous. 
 04 -  Pour the wet ingredients into the dry ingredients. Stir gently with a whisk or spatula just until the batter comes together and is slightly lumpy. Avoid overmixing. 
 05 -  Place a nonstick skillet or griddle over medium heat. Lightly brush with melted butter before cooking each batch. 
 06 -  Ladle about 1/4 cup of batter onto the skillet for each pancake. Cook until bubbles form on the surface and the edges are set, 2 to 3 minutes. Flip and cook an additional 1 to 2 minutes until golden brown and cooked through. Repeat with the remaining batter, greasing as needed. 
 07 -  Stack pancakes on individual plates while still warm. Place a generous scoop of vanilla ice cream on top of each stack. 
 08 -  Drizzle pancakes with root beer reduction. Optionally, garnish with whipped cream and a maraschino cherry. Serve immediately.