Preheat the oven to 325 degrees F, and mist three 6-inch diameter cake pans** with non-stick spray.  Cut three circles from parchment paper, and place them in the bottoms of each pan.

Place the flours, sugar, baking powder, baking soda, and salt in a medium bowl and whisk to combine.

Add the butter, and mix on medium-low speed until the mixture resembles damp sand.

Stir in the eggs, one at a time, until fully incorporated, stopping to scrape the bottom and sides of the bowl with a silicone spatula after each addition.

Add the milk, yogurt, and vanilla, and beat on medium-high speed for about 1 minute, to aerate the batter and strengthen the cake’s structure.

Transfer the batter to the prepared pans, and bake for 20-25 minutes, or until the cakes spring back when gently pressed and toothpick inserted in the center comes out clean or with a few moist crumbs.

Cool for twenty minutes, then unmold and place on  wire racks to cool completely.

Heat the milk in a small pot until small bubbles form around the edge, and wisps of steam are rising from the surface.

Place the yolks, sugar, cornstarch, and salt in a medium bowl and whisk to combine.

Add the hot milk to the egg mixture, a little at a time, whisking to combine.

When all the milk has been added, transfer the mixture back to the pot and place over medium-low heat.

Cook the pastry cream, whisking constantly, until thickened (the mixture should be the consistency of pudding).

Stir in the vanilla.

Pour the pastry cream through a fine mesh strainer, into a heat-safe bowl.  Use the back of a ladle to press the mixture through the sieve.

Press a layer of plastic wrap directly onto the surface, and refrigerate.

Place the cream cheese and powdered sugar in a large mixing bowl.  Fit the mixer with a whisk attachment, and whip on medium speed until the mixture is smooth.

Turn the mixer down to medium-low speed and pour the heavy cream down the side of the bowl in a very slow and steady stream.

When all the cream has been added, turn the mixer up to medium-high and whip until the frosting holds stiff peaks.

Place one layer of vanilla cake on a serving platter.  Spread half the pastry cream on the cake, and top with sliced bananas.  Spread a small amount of whipped cream frosting over the bananas, and top with the second cake layer.  

Repeat, topping with the third layer.  

Frost the cake with the whipped cream frosting, and garnish with homemade vanilla wafers and additional sliced bananas.