Preheat oven to 400°F.
Toss grapes in brandy in a small bowl.
Combine almonds with 2 tablespoons of sugar in a blender and pulse until finely ground.
With an electric mixer beat butter and 6 tablespoons sugar in a bowl until pale and fluffy. Add vanilla. Add eggs 1 at a time, beating well after each addition. Reduce speed to low and beat in ground almonds, flour, and salt until combined.
Drain brandy from grapes.
Divide batter among 4 buttered oven proof gratin dishes. Lightly press grapes into batter. Bake on a baking sheet until cakes are firm and just golden with slightly darker edges- approx 20 minutes.
Cool slightly in dishes before serving.