Line a small baking sheet with parchment paper.
Remove the pits from the dates, then press the dates down onto the parchment paper to form the base, making sure the dates are connected. You can flatten them down with wet fingers or in between two pieces of parchment paper
Next, spread the peanut butter over the flattened dates, then press the pretzels on top.
In a small bowl, melt the white chocolate in 30 second increments, mixing in between to prevent it from hardening. Spread the white chocolate layer over the pretzels.
Melt the blue chocolate in 30 second increments until smooth, then spoon it around the white chocolate. Using a toothpick, swirl the blue chocolate around. Alternatively, you can skip the blue chocolate swirl and sprinkle holiday sprinkles over the white chocolate.
Freeze the date bark for 1 hour. Remove from the freezer, add some sea salt and cut into pieces.
Keep refrigerated for up to 2 weeks, or freeze for up to 3 months.