Melt butter in saute pan, add in corn, red bell pepper and onion. Let saute until onion is translucent and corn has released some of it's sugars. Add in 1/2 of the basil leaves and a couple of twists of black pepper. Add in 1/4 cup heavy cream and reduce by half. Set aside to cool.
When cool, smash up a bit with a fork, stir in ricotta and cream cheese. Place wonton wrappers down (three at a time works) and in the center of each, place 1 1/2 t filling. Brush exposed wrapper with egg yolk, carefully place a second wrapper on top and carefully seal edges, making sure to get out any air bubbles. Cut with star cutter, work fingers around edges to make sure seal is tight. Set aside on floured baking sheet and continue to assemble.
When finished, boil water and gently add raviolis a few at a time, cooking for 2 minutes or until they float. Carefully remove and drain.
For Sauce: In clean saute pan, melt remaining 4 tablespoons butter, when melted, add in remaining basil, saute until crisp and butter is just very lightly browning. Add in remaining cream and reduce to thickened. Salt and pepper to taste, serve over raviolis immediately.