Preheat the oven to 425 degrees F (220 degrees C). Mix strawberries and 1/4 cup sugar in a large bowl; set aside.

Stir Bisquick mix, milk, 3 tablespoons sugar, and butter in a medium bowl until soft dough forms. Drop dough by 6 spoonfuls onto an ungreased cookie sheet.

Bake in the preheated oven until golden brown, 10 to 12 minutes. Meanwhile, beat whipping cream in a medium bowl with electric mixer on high speed until soft peaks form.

Split warm shortcakes; fill and top with strawberries and whipped cream.