FRESH STRAWBERRY SHEET CAKE

1 c. butter, softened 1 2/3 c. sugar 1 (3-oz.) box strawberry gelatin 3 eggs 2 ½ c. flour ½ t. baking powder ½ t. baking soda ¼ t. salt 1 c. whole buttermilk ½ c. finely chopped fresh strawberries…