1) Preheat the oven to 350F. Line a baking sheet with parchment paper.
2) Combine the vegetable oil and sugar in a large bowl, and whisk until smooth.
3) Add the tahini and 3 tablespoons of maple syrup, whisk again until smooth.
4) Add the flour, baking powder, and salt and keep mixing until it forms a soft dough.
5) Scoop out balls of cookie dough using a 1 1/2 tablespoon ice cream scoop.
6) Place the remaining maple syrup in a small bowl and place the chopped pistachios in a small plate.
7) Dip the bottom of each cookie dough ball into the maple syrup. Place each ball on top of the pistachio and slightly press to flatten the dough. Carefully dip the other side of the cookie into the maple syrup and lightly press into the chopped pistachios. Place cookies on the prepared baking sheet.
8) Bake the cookies for 13 minutes. ***If the cookies have spread a little, gently place the rim of a glass or a round cookie cutter over each cookie (make sure you don’t cut any of the edges). Gently move it in small circles in order to reshape the cookies and make them all even in size. You must do this immediately after they come out of the oven and they’re still hot.
9) Let the cookies cool completely before removing them from the baking sheet.