In a medium bowl, combine butter, sugar, vanilla and eggs. In another bowl, sift together flour, cocoa powder, baking powder and salt.
Add the wet ingredients to the dry ingredients, and stir until well mixed. Fold in the chocolate chips. Spread in a nonstick sprayed 8-inch square baking dish.
Bake 25 to 30 minutes until the edges of the brownies begin to pull away from the pan. Cool completely before cutting.
To make the sundaes, top warmed brownies with hot fudge, hazelnuts and a big scoop of vanilla ice cream. Sprinkle chopped basil on top.
Recipe by Flying on Jess Fuel at https://www.jessfuel.com/sweet-basil-brownie-sundaes/