On foil-lined baking sheet, toss berries and 1/2 cup sugar; cook at 425° until bubbly, 10 to 12 minutes. In bowl, whisk flour, baking powder and soda, the remaining 5 tsp. sugar and 1/2 tsp. salt. Stir in buttermilk, egg and 3 tbsp. butter. Brush griddle with remaining butter; heat over medium-low. Ladle 8 scant 1/4 cups batter onto griddle. Cook, turning once, until golden, 2 to 3 minutes per side. Top with strawberries.