Stir together flour, salt, and 3/4 cup of the sugar in a large saucepan. Whisk together milk and eggs in a bowl, and add it to the same saucepan. Cook over medium-low and whisk constantly until thickened, about 15 to 20 minutes. Remove from heat; stir in peanut butter, butter, and 1 1/2 teaspoons of the vanilla until the whole thing becomes smooth.

Fill a different large bowl with ice. Place the saucepan in the ice, and let it chill out, giving it an occasional stir, until the mixture is thoroughly chilled. Should take about 30 minutes.

While the mixture chills, cut bananas into 1/4-inch slices and crumble 4 cookies; you'll need these in a moment.

In the bowl of a heavy-duty stand mixer with whisk attachment, beat cream and remaining 1 teaspoon vanilla on high speed until foamy; gradually add remaining 6 tablespoons sugar, 1 tablespoon at a time, and beat at medium-high speed until stiff peaks form. Stop as soon as the peaks form, we don't wanna overdo it.

Line the bottom of a 13- x 9-inch baking dish with the cookies you prepared slightly overlapping. Top with half of the banana slices and half of the pudding mixture. Repeat layers once. Top with sweetened whipped cream. Cover and chill 2 to 24 hours. Top with reserved crumbled cookies and peanuts and sifted unsweetened cocoa.