Preheat the oven to 350 degrees F (175 degrees C).

Stir together flour and brown sugar in a medium bowl. Rub in butter using your hands or a pastry blender. Press into an ungreased 9-inch square pan.

Bake in the preheated oven until lightly browned at the edges, about 15 minutes. Set aside.

Beat eggs in a medium bowl until light. Mix together brown sugar, flour, baking powder, and salt; stir into eggs.

Mix in coconut, walnuts, and cherries; spread the batter evenly over the baked crust.

Return to the oven and bake until brown, about 25 minutes. Set aside to cool.

Mix confectioners' sugar, butter, water, and vanilla in a small bowl until smooth. Add more liquid if necessary for spreading.

Spread over cooled bars before cutting into squares.