Preheat the oven to 350°F. 

Whisk together almond flour, sugar, and salt. Cut butter into small pieces. Work vanilla and butter into flour mixture with a pastry cutter. Continue to mix with your hands until the dough forms into a ball and no visible butter pieces are left.

Press the mixture into a half-inch thick rectangle on a baking sheet lined with parchment paper. Score into rectangles or squares with a butter knife, then poke each cookie with a fork or toothpick.

Bake for 10-12 minutes or till edges turn golden. Don't let the tops brown. 

Important: let the cookies cool on the baking sheet for at least 10 minutes before lifting the parchment with the cookies off the sheet and onto a cooling rack. Cut gently with a sharp knife along the scoring lines once cool. 

To temper the chocolate, melt the chocolate chips in the microwave 10 seconds at a time, and stop when a few chips still hold their shape. Stir until smooth. (To melt on the stove, use a double boiler or bain-marie to melt until a few chips still hold their shape. Stir until smooth.)

Dip one end of each cooled cookie into the chocolate, and let it stand on the bare end leaning against the cooled baking sheet until the chocolate re-hardens.

Grind pistachios in a food processor, or chop to a fine powder. While the chocolate is still warm, sprinkle the chocolate-dipped edge with the ground pistachios. Allow chocolate to harden completely before storing in an airtight container.