The ULTIMATE Banana Pudding Cupcakes

In a medium bowl, whisk together the egg (or egg yolks), sugar, cornstarch and salt aggressively for 1-2 minutes, until the mixture becomes smooth and runny, with no more chunks.
3 large egg yolks (or 1 egg)* room temperature, 45 grams granulated sugar scant cup, 30 grams cornstarch, tiny pinch fine sea salt
In a medium saucepan, heat the milk over medium heat, just until it comes to a simmer.
240 mL whole milk
Temper the eggs by streaming half of the milk into the egg mixture while continuing to whisk.
Dump the whole mixture back into the saucepan and cook over medium-low heat, while whisking continuously.
Within 1-3 minutes, the mixture should start to thicken, continue whisking, making sure to scrape the edges and center of the pan.
Once it's starting to stick to the pan, whisk aggressively for another 30-60 seconds. Remove from the heat and pour into a bowl with the butter and vanilla.
2 tsp vanilla bean paste or extract, 42 grams salted butter room temperature
Allow the heat from the pastry cream to melt the butter for a second and then gently whisk it. It may separate at first but it'll come back together as you whisk.
The pastry cream should be smooth and silky now, if you have any lumps, feel free to push it though a sieve.

Preheat the oven to 350F/177C convection (325F/163C conventional) and line 13 muffin tins with cupcake liners (preferably a light colored pan).
In a medium bowl, whisk together the cake flour, baking powder, salt and sugar until they're evenly distributed (whisk well).
180 grams cake flour spooned and leveled, 1/2 tbsp baking powder, 1/2 tsp fine sea salt, 200 grams granulated sugar
Add the oil and butter to the dry ingredients and beat together until they're combined.
56 grams salted butter, 60 mL canola oil or any neutral oil
Add the egg and vanilla extract and paste and mix until they're fully combined.
1 large eggs room temperature, 2 tsp vanilla extract
Add the sour cream and turn the mixer to low speed, while streaming the milk in. Scrape the edge of the bowl and mix just until the cupcake batter is smooth.
113 grams sour cream room temperature, 80 mL milk room temperature
Place a vanilla wafer cookie on the bottom of each cupcake liner and then fill the cupcake liners about 3/4 full. I recommend weighing them so each cupcake has 45-50 grams of batter.
13 vanilla wafers
Bake for about 18-20 minutes. They are done when you press on the center of the cupcake and it springs back or when a toothpick inserted comes out clean.
Remove them from the oven and let them cool in the cupcake pan for 10 minutes, then move them to a cooling rack. Allow the cupcakes to cool completely before frosting.

Sift the powdered sugar and salt into the bowl of the stand mixer, fit with a whisk attachment (or a large bowl with a handheld mixer).
15 grams powdered sugar , tiny pinch fine sea salt
Pour the heavy whipping cream on top, along with the vanilla and turn the mixer up to medium speed for a few seconds until it starts to thicken (if you go full speed it will splash everywhere).
120 mL heavy whipping cream cold, 2 tsp vanilla bean paste or extract
Turn the mixer up to medium-high and whip just until it holds stiff peaks.
If you over-mix and it’s no longer smooth, add a little more cream and fold it in until it’s smooth again.

Once the cakes and the pastry cream have cooled, slice the bananas and toss them into a bowl with the lemon juice (you won't taste the lemon juice but it'll prevent them from turning brown).
1 large bananas sliced (ripe enough to eat but not over-ripe), 15 mL lemon juice
Place the first layer of cake onto a flat surface and spread a good layer of pastry cream on top.
Then a single layer of banana slices on top of the pastry cream and followed by a layer of vanilla wafer cookies (I used minis so I left them whole).
2 vanilla wafers crushed
Top with a generous layer of whipped cream and then another layer of cake. Repeat and then top with the last layer of cake.
Spread the rest of the whipped cream on top and decorate with some bananas and wafer cookies.
Refrigerate the cake for at least a few hours to set and slice easier. Serve cold or slightly chilled. Store refrigerated.