1Heat oven to 350^. Grease 9-inch pie dish.
Place all ingredients in blender container.
Cover and blend on high for 1 minute.
Pour into pie plate. Bake until no indentations remains when lightly touched in center, about 30 minutes. Cool completely. Top with sweetened whipped cream if desired.
High altitude 3500-6500 feet.
Heat oven to 375^ Omit chocolate. Add 1/4 cup plus 2 Tablespoons cocoa and 3 Tablespoons flour. Decrease Bisquick to 1/4 cup.