01 -
Preheat oven to 175°C. Grease a 23x33 cm baking pan or line with parchment paper for easy removal.
02 -
In a large bowl, beat softened butter, brown sugar, and granulated sugar until creamy and thoroughly combined.
03 -
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
04 -
In a separate bowl, whisk together flour, baking soda, salt, and graham cracker crumbs.
05 -
Gradually add the dry mixture to the wet mixture, mixing until just combined. Do not overmix.
06 -
Gently fold in semi-sweet chocolate chips and mini marshmallows, ensuring even distribution.
07 -
Spread half of the dough evenly in the prepared pan and press gently with a spatula.
08 -
Evenly distribute chocolate chunks or bar pieces over the dough layer.
09 -
Crumble the remaining dough over the chocolate layer, spreading as evenly as possible.
10 -
Bake for 25–30 minutes or until the edges are golden and a toothpick inserted into the centre comes out with moist crumbs.
11 -
Remove from oven and let cool in the pan for 10 minutes. While warm, top with extra mini marshmallows and drizzle melted chocolate, if desired.
12 -
Allow to cool fully before cutting into squares. Serve once set.