Place the sliced strawberries in a small bowl.
Sprinkle the sugar over the strawberries and gently toss to combine.
Set aside for 10 minutes to allow the berries to release their natural juices.
In a separate bowl, whisk together the melted butter and balsamic vinegar.
Brush the mixture evenly over both cut sides of each angel food cake slice.
Lightly grease the grill rack and preheat the grill to medium heat.
Place the cake slices on the grill.
Grill for 1–2 minutes per side or until lightly golden and toasted.
Remove the cake from the grill and transfer to serving plates.
Top each serving of Grilled Angel Food Cake with Strawberries with the prepared strawberries.
Add vanilla ice cream and blueberry syrup if desired.
Serve immediately and enjoy.