Preheat the oven to 350 degrees F. Butter a 9-inch pie pan. place graham crackers in a food processor and process to crumbs Add the melted butter and sugar and pulse or stir until combined. Press the mixture into the bottom and sides of the pie pan. Bake the crust until set, 8 minutes. Set aside on a wire rack; leave the oven on.
For the filling
Meanwhile, in a small pan over low heat, cook raspberries with the sugar for 10 minutes then strain. Pour raspberries over the cooled pie crust. In a food processor, beat the egg yolks and lime zest until very fluffy, about 5 minutes. Gradually add the condensed milk and continue to beat until thick, 3 or 4 minutes longer. Lower the mixer speed and slowly add the lime juice, mixing just until combined, no longer. Pour the mixture into the crust. Bake for 10 minutes or until the filling has set. Cool on a wire rack, then refrigerate. For the topping:
For the whipped cream
Whip the cream and the confectioners' sugar together. Put the whipped cream into a pastry bag with a decorative tip and decorate the pie with it.