Mix butter, honey, brown sugar, vanilla, and lime juice in a small saucepan. Bring to simmer over medium heat; whisking until smooth.

Cut cored pineapple into rings. Brush both sides of pineapple slices with sauce. Grill 1-2 min per side. Remove from grill.

Cut pineapple rings into cubes, place into large bowl. Cut bananas into slices. Add any remaining sauce. Serve and enjoy!