Line an 8 ½" x 4 ½" loaf pan with a parchment sling.
In a skillet over medium heat, toast the oats, stirring occasionally, until fragrant and a shade or two darker, 5 to 7 minutes. Immediately transfer the oats to the bowl of a food processor.
Add the cashews and salt to the food processor and pulse until the texture is a coarse meal (slightly coarser than breadcrumbs), 20 to 30 seconds. Add the dates and pulse until they’re smaller, about 20 seconds.
Add the coconut oil, honey, and vanilla and pulse until the mixture comes together, about 10 to 15 seconds.
Transfer the mixture to the prepared loaf pan and press into an even layer.
Dice the last 1 tablespoon of chopped dates into smaller pieces.
In a small microwave-safe bowl, combine the chocolate and coconut oil. Melt in the microwave in 20-second increments until fully melted; stir until smooth.
Pour the melted chocolate mixture over the bars and tilt the pan so that it evenly coats the top. Sprinkle with the diced dates and flaky sea salt.
Transfer the bars to the refrigerator to set, uncovered, for about 1 hour.
Run an offset spatula or nylon spreader around the edges of the pan, then remove the energy bars and slice into bars or squares.
