Instructions

• Preheat oven to 325°F. Line an 8 x 8 x 2-inch baking dish with parchment paper, leaving an overhang for easy removal.
• In a medium bowl combine 9 sheets crushed chocolate graham crackers, 2 tablespoons granulated sugar, and 6 tablespoons melted unsalted butter. Stir until evenly moistened.
• Press the crumb mixture firmly and evenly into the bottom of the prepared baking dish. Bake for 10 minutes. Remove from oven and let the crust cool completely in the pan on a wire rack.
• Place 4 ounces unsweetened baking chocolate in a microwave-safe bowl. Microwave in 30-second intervals, stirring between each interval, until the chocolate is fully melted and smooth. Set aside and let the chocolate cool to room temperature.
• In the bowl of a stand mixer fitted with the whisk attachment, add 1 cup softened salted butter and 1 ½ cups powdered sugar. Beat on medium speed for about 2 minutes, until creamy and smooth. Scrape down the bowl as needed.
• Add the cooled melted chocolate and 1 teaspoon vanilla extract to the butter-sugar mixture. Beat until fully incorporated, scraping the bowl once or twice.
• With the whisk attachment on medium speed, add the 4 large eggs one at a time. After adding each egg, beat for 5 minutes before adding the next. Scrape down the bowl between additions. (You will beat a total of about 20 minutes.)
• Pour the chocolate filling over the cooled graham cracker crust and smooth the top with a spatula.
• Refrigerate for at least 3 hours, or until the filling is set.
• Use the parchment overhang to lift the bars from the pan, slice, and serve topped with fresh whipped cream and chocolate shavings, if desired.