Line a standard loaf pan with parchment paper, leaving enough overhang on the sides to easily lift the bars out later.

Add the pitted Medjool dates, oat flour, sunflower seed butter, cocoa powder, chocolate collagen powder, vanilla extract, and 1 tablespoon milk to a food processor.

Process until the ingredients begin to come together into a thick, fudgy dough. If the mixture seems too dry or crumbly, add additional milk 1 tablespoon at a time, processing between each addition. Depending on how soft your dates are and the consistency of your sunflower seed butter, you may need anywhere from 1–4 tablespoons total.

Transfer the mixture to the prepared loaf pan. Press it down very firmly and evenly, smoothing the top with a spatula or your hands.

Pour the melted chocolate over the top and spread it into an even layer.

Transfer the loaf pan to the freezer for 2–4 hours, or until the bars are completely firm.

Lift the mixture from the pan using the parchment paper. Allow it to sit at room temperature for a few minutes if needed for easier slicing, then cut into 8 bars.

Store the bars in an airtight container in the freezer. Let one sit out for a few minutes before eating if you prefer a softer, fudgier texture.