Let the cake cool for 15 minutes before inverting it onto a cooling rack with a sheet pan underneath to catch excess drippings.
Bring the glaze to a boil for 1 minute to dissolve the sugar.
Poke holes in the top of the still-warm cake with a skewer or toothpick and brush the glaze over. If there is any excess glaze you can scoop it back up and brush until there is no more glaze.
Just before serving dust with Powdered sugar if desired.
This recipe was adjusted for high-altitude baking. To make it for you lowlanders, increase sugar to 2 1/2 cups, baking powder to 1 teaspoon, and decrease the sour cream to 2/3 cup. Baking times may vary slightly.