Preheat the oven to 350 degrees F. Line half sheet pans with parchment paper and set aside.
In a large bowl with a handheld electric mixer or a stand mixer fitted with the paddle attachment, beat the sweetened condensed milk and butter until smooth and creamy, 1-2 minutes.
Add the graham cracker crumbs, flour, baking powder and salt and mix until mostly combined. It's ok if a few dry streaks remain.
Stir in the chocolate chips, coconut, and nuts (if using).
Drop the cookie dough by rounded tablespoons onto ungreased cookie sheets (I use a #40 medium cookie scoop).
Bake for 8 to 10 minutes.
Let the cookie rest on the baking sheet for 1-2 minutes before removing to cool completely on a wire rack.
