Crust: Preheat oven to 350 degrees. Combine graham crackers, sugar, and butter. Press into two 8-ounce ramekins. Place on a baking sheet with one unpeeled banana. Bake for 10 minutes, until the banana is soft with a black peel, and the crusts are set.
Filling: Without heat, whisk sugar, cornstarch, salt, and egg yolk together in a small saucepan. Slowly whisk in the milk until mostly smooth. Move your pan to the stove and bring to a low simmer over low heat, whisking frequently (it will get a little lumpy – that’s okay). Continue to heat gently for a few minutes until you get a nice thick pudding consistency. Remove from heat and stir in butter and vanilla.
Blend: Transfer the cooled pudding to a blender or food processor with the roasted banana. Blend until mostly smooth (this should help the filling loosen up a little bit).
To assemble
Assemble: Top the baked crusts with slices of banana. Pour the filling over the top. Cover and refrigerate for 2-3 hours until set. Top with whipped cream and dive into that cold, sweet, creamy goodness.