Preheat the convection oven to 350°F (180°C) and prepare a standard 12-cup muffin tin with non-stick spray or high-quality silicone liners.

In a primary mixing bowl, combine the mashed bananas, rolled oats, and protein powder. Stir vigorously until a uniform, thick dough is achieved with no dry powder remaining.

Calibrate the distribution of the dough evenly across the 12 muffin cups. Use the back of a damp spoon or a small measuring cup to press the mixture firmly into a flat, compact disc at the bottom of each cavity.

Bake for 15 minutes on the middle rack until the bases are structurally set and the edges exhibit slight golden-brown caramelization. Remove from the oven and allow to cool completely in the pan to ensure structural integrity.

Liquefy the peanut butter by heating it in a microwave-safe bowl for 20-30 seconds until the viscosity is low enough for pouring. Spoon exactly 1 teaspoon of peanut butter onto each cooled oat base, spreading to the perimeter.

Place the muffin tin in the freezer for 15 minutes to facilitate the thermal set of the peanut butter layer, preventing interlayer mixing.

Temper the dark chocolate using a double boiler or controlled microwave intervals. Spoon the melted chocolate over the solidified peanut butter layer in each cup, tilting the pan to ensure full surface coverage.

Immediately garnish with a localized pinch of flaky sea salt for flavor contrast. Return the tin to the freezer for an additional 10 minutes until the chocolate shell reaches full hardness.

De-mold the cups and store in an airtight container within a refrigerated environment (34°F-38°F) for up to 7 days.