Preheat the oven to 350°F. Line a 9-inch square baking pan with parchment paper, leaving an overhang on two opposite sides to lift the bars out later.

In the bowl of a large food processor, combine the graham cracker pieces, chopped Mexican chocolate, melted butter, and the 1 teaspoon ground ancho chile powder. Process until the mixture resembles wet sand.

Press the processed mixture firmly and evenly into the bottom of the prepared pan to form the crust.

Coarsely chop the pecans, pepitas, and shredded sweetened coconut and place them in a large bowl. Add the butterscotch chips and the 14-ounce can of sweetened condensed milk; stir until all pieces are evenly coated.

Spread the nut/coconut/chip mixture in an even layer over the crust, pressing lightly to level the top.

Bake for 40 to 45 minutes, until the top is deep golden brown and the edges are crisp.

Remove from the oven and set the pan on a wire rack. Cool at least 30 minutes before using the parchment overhang to lift the slab from the pan and cut into bars.