Heat the creamy base. Add the cottage cheese, evaporated milk, and 1/3 cup sugar to a blender and puree until smooth. Add the cottage cheese mixture, along with the milk, split vanilla bean and its seeds to a large, heavy-bottomed saucepan and turn heat on medium. Heat till frothy, whisking to dissolve sugar while heating. Remove from the heat.
Beat the egg mixture. In a medium bowl, combine the egg yolks, whole eggs, cornstarch, and 2/3 cup sugar and whisk until pale yellow in color. Set aside.
Finish the custard. Whisk 1/2 cup of the hot cottage cream mixture into the egg yolk mixture, then gradually add the remaining egg mixture to the pot with the hot cream, whisking constantly. Heat, stirring constantly with a large wooden spoon, to cook out the cornstarch and thicken the mixture. Be patient here, this will take around 5 minutes. (If the mixture gets lumpy, remove from the heat and beat with a whisk or an electric mixer until thick and smooth.) Once thickened, strain through a fine-mesh strainer into a clean bowl. Let the mixture cool slightly, then cover with parchment or plastic wrap, pressing against the surface of the custard to prevent a skin from forming. Chill in the refrigerator for about 4 hours.
Meanwhile, prepare the crust. Preheat the oven to 350°F and arrange a rack in the center of the oven. To a medium bowl, add the graham cracker crumbs, ground flax and sugar and whisk to combine. Then, add the melted butter and mix until the consistency resembles wet sand. Add the graham mixture to a standard pie dish, and press gently to create an even layer on the bottom and sides. I like to use the bottom of a flat measuring cup for this. Bake for about 20 minutes, or until golden brown, then remove and cool completely.
Assemble. Spread 1/2 cup of the custard evenly over the bottom of the cooled crust and smooth it out. Then, arrange enough banana slices to cover, in a tight, tiled pattern over the custard, pressing down with your hands to pack them firmly. For the second layer, spread 3/4 cup of the custard onto the bananas, spreading evenly, then arrange enough bananas on top to cover. Repeat for the third layer, starting the bananas about 1/2 inch away from the outer edge. Spread the remaining 1 cup of custard evenly over the bananas so no banana is showing, then cover with plastic wrap and chill for at least 4 hours or overnight.
Make the whip. When the pie has chilled, whip the cream. To a medium bowl, add the heavy cream and whip until slightly thickened. Add the collagen peptides, the remaining tablespoon of sugar and vanilla extract and continue to whip until stiff peaks form.
Remove the pie from the refrigerator and cover the custard with whipped cream. You can do a fun pattern if you’d like or just leave it smooth. Top with chocolate shavings if you’d like, then slice and serve!