Preheat oven to 180°C (350°F). Grease and line two 8-inch round cake pans.
Cream butter and sugar until fluffy. Add eggs one by one, then mix in vanilla and brewed coffee.
Sift flour and baking powder, fold into wet ingredients until smooth.
Divide batter into pans and bake for 25–30 minutes. Test with a toothpick. Let cool.
For frosting: Beat butter until creamy, add powdered sugar gradually, then caramel sauce and milk. Whip until smooth.
Assemble cake: Layer sponge with frosting, cover top and sides, drizzle salted caramel.
Garnish with chocolate shavings or cocoa powder if desired.