First, make the compote. Combine all of the ingredients in a pot (minus the butter, if using) and bring to a boil. Reduce to a simmer and cook for 8 minutes or until the grapes have all burst and the liquid is very syrupy. Remove the star anise, stir in the butter if using, then pour into a bowl. Set aside.
For the pancakes: whisk together the dry ingredients. In a separate bowl, whisk together the sour cream, the eggs, and the vanilla; then add to the wet ingredients to the dry ingredients and stir just until combined.
Preheat your oven to 250. In a non-stick skillet, melt the butter until foamy, then pour in 1/2 cup of batter for each pancake — three pancakes per batch. Cook for two minutes; when bubbly and brown on the bottom, carefully flip (it’s tricky, they’re wet) and finish on the other side. Remove to a cookie sheet, keep warm in the oven, while you finish the remaining pancakes.
To serve: place the pancakes on a plate, dust with powdered sugar, and top with the compote. Serve the rest of the compote on the side.