Begin by blitzing the dates in your food processor until broken up into small pieces. Add the rest of the ingredients, minus the pretzels, and blend until you have a coarse meal. Pinch a little of the mixture between your fingers, if it sticks together, great. If it feels too dry, add 1/2 tablespoon of coconut oil and pulse to incorporate.
Next, pour in the pretzels and pulse a few times to break them up. I like having some larger pieces to create texture.
Scoop the mixture into an 8x8 parchment paper lined brownie pan, or a large pyrex container. I used a 9x7 pyrex container since it has a lid and makes for easy storage. Be sure and cut the parchment paper long enough so the sides reach the top of the container. This will allow you to lift out the frozen block and cut it into bars. Press the mixture down into the container with your fingers, as firmly as possible. Once you’ve done as much as you can with your hands, use the bottom of a water glass to press down even more and to create a flat surface. Cover and freeze for 30 minutes.
Melt together the dark chocolate chips and coconut oil, then stir in the peppermint extract. Spoon the chocolate over the frozen bars into a thin, even layer, then crush a couple pretzels with your rolling pin and sprinkle on top of the chocolate. Freeze for another 30 minutes.
Once the bars are completely frozen, remove from the freezer and carefully lift the block out of the container using the edges of the parchment paper. Using a long knife, carefully cut it into bars. I prefer smaller bars because they are so rich and filling. Place the cut bars back into the container using the parchment paper between layers if necessary, cover, and keep frozen until you’re ready for snack!