Add dates to a heatproof bowl. Pour over boiling water and soak for 15 minutes then drain.

In a large food processor, blend the soaked dates, melted chocolate, coconut oil, and vanilla until smooth. Add the almond flour, oat flour, black cocoa, regular cocoa, and salt and blend until a cohesive dough forms.

Divide the dough in half and place each portion between two sheets of parchment paper. Roll each portion into an 8 × 4-inch rectangle about ⅛-inch thick, trimming the edges as needed for clean, even layers. Carefully transfer each rectangle to a parchment-lined baking sheet and chill until firm.

Meanwhile, make the ice cream. In a mixing bowl, whisk together greek yogurt, protein powder, vanilla, and salt. Gently fold in thawed truwhip topping until combined.

Grease a 8x4" loaf pan with nonstick cooking spray. Line with parchment paper, leaving a some overhang. Spray again with nonstick cooking spray.

Place one cookie layer in the bottom of the pan. Spread the vanilla ice cream filling evenly over the cookie, then top with the second cookie layer, gently pressing down to create an even sandwich.

Freeze until completely firm, then remove from the pan and slice into individual sandwiches. Sprinkle over flaky sea salt before serving.