Place cashews and pecans into a food processor and process until the mixture resembles a smooth nut butter, stopping to scrape down the side of the bowl if necessary. This can take 5 to 10 minutes of processing, so be patient.
Process in the sugars, butter and vanilla. The sweeteners will at first thicken the nut butter quite a bit, but keep processing and the heat will eventually melt the sugar and smooth out the nut butter. Once again, if it still looks too thick, keep processing!
Now here is the hard part – when your nut butter is finished processing, you need to pop it into the fridge to chill. If you don’t chill it, the chocolate chips will melt right into the nut butter and turn everything brown (yes, this happened!). Once it’s chilled, about 25 minutes, stir in the mini chocolate chips. This creates about about 1 1/2 cups of nut butter, more than you will need to fill all 24 of the chocolate cups. Remaining nut butter can be stored in fridge for 2-3 weeks, use on crackers ort toast.
While the "cookie dough" is cooling off, line a mini muffin pan with with 24 liners. Melt 1 1/4 cups of chocolate chips (I do mine in the microwave, heating on full power for 20 seconds, stir, 30 seconds again, and stir until melted). Drop 1/2-1 teaspoon of chocolate into each liner, then use a pastry brush to brush chocolate up the sides of the liner. Place in the freezer for 20 minutes. By this point the "cookie dough" should be cool.
Remove muffin tin and cookie dough, then place 1 teaspoon of cookie dough into the chocolate cups. Place back in the freezer while you melt the remaining chocolate. Melt the remaining chocolate chips, then cover each cookie dough top with chocolate, smoothing with a spoon. Freeze again for 15-20 minutes. These are fine if left out at room temperature for a few hours (they may soften a bit) but I like them best stored in the fridge.
*Instead of making the cashew butter you can use peanut butter or almond butter and just mix in the sugars, butter, vanilla and chocolate chips