Scrape off and discard the frosting from the cupcakes; crumble the cupcakes into crumbs. Press all but 1/4 cup crumbs into the bottom and up the sides of a 9-inch deep-dish pie plate. Freeze 30 minutes.
Meanwhile, let the ice cream and sorbet soften at room temperature, about 15 minutes. Spread the ice cream evenly over the crust using an offset spatula or rubber spatula; spread the sorbet on top. (Return the pie to the freezer between layers if the ice cream gets too soft.) Freeze while you make the whipped cream.
Beat the heavy cream and confectioners' sugar in a large bowl with a mixer on medium-high speed until soft peaks form, about 3 minutes. Top the pie with the whipped cream and sprinkle the reserved cupcake crumbs around the edge. Freeze until firm, at least 4 hours or overnight.