Heat the oven to 350°. Spread the cacao beans on a parchment paper—lined baking sheet and bake, stirring occasionally, until toasted and the beans smell like brownies, about 30 minutes. Transfer the baking sheet to a rack and let cool for 8 hours.
Divide the beans between 2 large plastic bags and, using a rolling pin, gently crack the beans into nibs. Pour the nibs into a large bowl and shake gently to allow the lighter husks to float to the top. Remove the husks and continue shaking and lifting the nibs until the husks float to the top and can be removed.
Turn on the melanger (see “Why You Need a Melanger”) and let it run for 10 minutes to warm up. Pour 1 cup of the cracked cocoa nibs into the melanger, cover with the lid, and process until the nibs form a paste, about 15 minutes. Repeat, adding 1 cup of the nibs to the melanger every 15 minutes to form a paste before adding the next cup. Once all the nibs are added, continue processing until the nibs are completely liquefied, about 45 minutes. Pour the sugar into the liquid, replace the cover, and process until the sugar dissolves and the chocolate is reliquefied and smooth, about 4 hours.
Meanwhile, heat the oil in a medium skillet over medium. Add the pepitas and chile powder and cook, stirring, until lightly toasted, about 3 minutes. Pour the pepitas into a bowl and let cool.
To temper the chocolate, scrape two-thirds of the liquid chocolate into a large glass bowl and place the bowl over a saucepan of barely simmering water. Using a rubber spatula, stir the chocolate constantly until it is heated to 115°. Remove the bowl from the saucepan and stir in the remaining liquid chocolate until the entire mixture cools to 80°. Return the bowl to the saucepan and, stirring steadily, heat to 88°. Remove the bowl from the saucepan and pour the tempered chocolate onto 2 parchment paper—lined baking sheets. Using an offset spatula, spread the chocolate into a 1⁄4-inch-thick rectangle on each sheet. Sprinkle both sheets evenly with the pepitas and turbinado sugar and let cool until set. Break into shards and store in an airtight conatiner for up to 1 week.