01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper.
02 - In a large mixing bowl, whisk together flour, baking powder, and salt. Cut in the cold butter using a pastry cutter or fork until mixture resembles coarse crumbs.
03 - Stir in the milk until a soft dough forms, being careful not to overmix. Press dough evenly into the prepared pan.
04 - In a small bowl, combine melted butter, Buffalo sauce, and ranch seasoning. Drizzle the mixture evenly over the dough and gently swirl with a knife.
05 - Bake for 18 minutes, until the biscuit base is just beginning to turn golden.
06 - Remove pan from oven and sprinkle with chocolate chips, mini marshmallows, and crumbled graham crackers. Return to oven and bake for 7-8 minutes, until marshmallows are puffed and lightly golden.
07 - Let cool in the pan for 10 minutes, then lift out using parchment paper. Slice into bars and serve warm or at room temperature.