Pour half and half into a large saucepan. Add seeds of vanilla bean and the vanilla bean pod, and nutmeg to the half and half. Heat over medium heat until it is just simmering.

Meanwhile, whisk together 3/4 cup sugar, the cornstarch, salt, and egg yolks until slightly pale and fluffy, about 1 minute (it will be very thick at first, keep whisking).

Once half and half is simmering, slowly pour 1 cup hot half and half into the sugar-egg yolk mixture while whisking. Then pour that sugar-egg yolk mixture into the saucepan while whisking vigorously.

Cook and whisk vigorously (while scraping down the bottom edges as you whisk), until thickened and large bubbles appear. Then cook and whisk for 30 seconds longer.

Immediately pour and scrape mixture into a heatproof bowl. Add butter and stir mixture well. If using vanilla extract instead of a vanilla bean, add 2 tsp at this point and stir in. Cover with plastic wrap clinging it over the top of the pudding to prevent skin from forming and chill for 2 hours or until cooled.

Align 30 vanilla wafer cookies into the bottom of an 8 by 8 by 2-inch baking dish, slightly overlapping them.

Remove vanilla bean from pudding and dollop half of the pudding over the cookies in spoonfuls then spread evenly. Slice 2 of the bananas into 1/4-inch thick slices and align evenly over pudding layer, brushing the top of bananas lightly with lemon juice.

Align 30 more vanilla wafer cookies over banana layer, followed by spreading over the remaining 1/2 of the pudding. Cover and chill for at least 2 hours.

In a mixing bowl using an electric hand mixer, whip together the heavy cream, 2 Tbsp granulated sugar, and 1/2 tsp vanilla on medium speed until it thickens then increase to high speed and whip until very stiff peaks form.

Cut the remaining 2 bananas into 1/4-inch slices. Spread slices evenly over the pudding layer then brush with lemon juice.

Spread whipped topping evenly over bananas. If desired, garnish the top with some of the remaining cookies, slightly crushed, and some banana slices, adding them just before serving so they don't brown.

Enjoy your delicious homemade banana pudding!