01 -  Preheat oven to 375°F (190°C). Grease or line a standard loaf pan with parchment paper. 
 02 -  Combine all-purpose flour, baking powder, baking soda, salt, and granulated sugar in a large mixing bowl. Whisk until evenly blended. 
 03 -  Add cold cubed butter to dry mixture. Use a pastry cutter or fork to work butter into flour until the mixture resembles coarse crumbs. 
 04 -  Whisk together cold buttermilk and egg in a separate small bowl. Pour the mixture over the dry ingredients. 
 05 -  Gently mix until just combined, taking care not to overwork the dough. 
 06 -  Add shredded cheddar cheese, diced jalapeños, and chopped chives. Fold gently to distribute. 
 07 -  Gently fold in mini marshmallows, semi-sweet chocolate chips, and crushed graham crackers. Avoid overmixing to preserve texture. 
 08 -  Spoon the thick batter evenly into the prepared loaf pan, smoothing the top. Brush with melted butter, sprinkle extra cheddar, and finish with crushed graham crackers. 
 09 -  Place in oven and bake for 28 to 33 minutes, until golden brown and a toothpick inserted into the center yields a few moist crumbs. 
 10 -  Let the loaf cool in the pan for 10 minutes, then transfer to a wire rack. Slice and serve warm for a gooey texture.