CLASSIC RECIPE S'mores Sheet Cake

Ingredients

• 16 to 18 graham crackers
• 1/2 cup (125 ml) unsalted butted, melted
• 1/2 cup (125 ml) canola or coconut oil
• 2 100 g Lindt Milk Chocolate CLASSIC RECIPE bar, divided
• 2 cups (500 ml) all purpose flour
• 1/3 cup (80 ml) cocoa powder
• 1 tsp (5 ml) instant coffee or espresso powder (optional)
• 2 tsp (10 ml) baking powder
• 1 tsp (5 ml) kosher salt
• 1 cup (250 ml) lightly packed light brown sugar
• 2 tsp (10 ml) vanilla extract
• 2 large eggs, room temperature
• 1 1/2 cup (375 ml) buttermilk
• 1 250 g bag large marshmallows