Line an 8x8 inch square baking dish with parchment paper.

In the bowl of a food processor, combine the dates, cashews, tahini, and vanilla. Pulse until well combined and no large chunks remain, 3-5 minutes. Press the mixture evenly into the prepared baking dish. Transfer to the freezer and freeze until firm, 30 minutes to 1 hour.

Melt the dark chocolate in the microwave in 30-second intervals, stirring until melted and smooth. Let cool for 10 minutes.

Cut the firm bar mixture into 16 bars. Dip each bar into the melted chocolate, ensuring it's fully coated. Top immediately with toasted sesame seeds or dried fruit, if desired.

Let the chocolate set up on a wire rack or parchment paper for about 10 minutes. Store the finished bars in an airtight container in the fridge.