Place the chopped dark chocolate and butter in a microwave-safe bowl. Microwave in 30-second bursts, stirring each time, until the mixture is smooth, glossy, and fragrant. This should take about 1-2 minutes in total.
Add the sweetened condensed milk to the melted chocolate and butter. Stir well until fully combined, creating a thick, shiny mixture that’s easy to pour and spread.
Sift the cocoa powder into the mixture and add the vanilla extract. Mix thoroughly until the mixture is smooth, dark, and velvety, with no lumps remaining.
Gently fold in the crushed graham crackers until evenly distributed, giving the bars a satisfying crunch in every bite.
Line your loaf pan with parchment paper, leaving some overhang for easy removal. Pour the chocolate mixture into the pan and use a spatula to spread it evenly across the surface.
Tap the pan gently on the counter to settle the mixture and release any trapped air bubbles, ensuring a smooth, even surface.
Place the pan in the fridge and chill for at least 3 hours, or until the mixture is firm and set. For quicker results, you can freeze it for about 1 hour, but be cautious of cracking.
Once set, lift the chocolate slab out of the pan using the parchment overhang. Use a sharp knife, wiped with warm water between cuts, to slice into bars or squares of your desired size.
Optionally, sprinkle flaky sea salt or chopped nuts on top of each bar immediately after slicing for extra flavor and texture.
Enjoy these glossy, fudgy bars straight from the fridge for the best texture and flavor. Store any leftovers in an airtight container in the fridge for up to a week, or freeze for longer storage.
