• Prep oven and pan. Position a rack in the center of your oven and preheat the oven to 350°C (180°C). Line an 8x8” pan with parchment paper, or grease with non-stick cooking spray. See note below about using a metal or glass pan.
• Line the bottom of the pan with graham crackers. You may need to break the 5th cracker to make it fit into the bottom of the pan. 5 full-sized graham crackers

Make the brownie:

• Combine dry ingredients. In a small mixing bowl, whisk together the flour, salt, and baking powder. Set aside. ½ cup plus 1 tablespoons (80 g) all-purpose flour ½ teaspoon salt ¼ teaspoon baking powder
• Combine wet ingredients. In a large mixing bowl, whisk together the granulated sugar, eggs, brown sugar, oil, and vanilla. ¾ cups (150 g) granulated sugar 2 large eggs ¼ cup (50 g) packed light brown sugar ¼ cup (60 ml) canola oil 1 teaspoons vanilla extract
• Combine butter and chocolate. In a small saucepan on the stove, over low heat, melt and stir together the butter and chopped chocolate. Stir frequently to keep the chocolate from burning. Remove from the heat and stir in the cocoa powder, whisking to combine. ¼ cup (½ stick, 57 g) unsalted butter 4 ounces semi-sweet or bittersweet chocolate 2 Tablespoons (11 g) Dutch process cocoa powder
• Add chocolate mixture to sugar mixture. Whisk the chocolate/butter mixture into the sugar/egg mixture until smooth and combined.
• Add dry ingredients. Stir, using a spatula (or wooden spoon) in the dry ingredients until just combined.
• Assemble brownies. Spread the brownie batter on top of the graham cracker crust.
• Bake brownies. Bake for 22 to 27 minutes until a toothpick inserted in the center comes out with a few moist crumbs clinging to it. Transfer the pan to a wire rack to cool completely before cutting into bars and serving.

Make the frosting

• Heat egg whites. Place egg whites, sugar, and cream of tartar in the heatproof bowl of an electric mixer. Set over a saucepan with simmering water. Whisk constantly until sugar is dissolved and whites are warm to the touch, or 160F, about 3 to 5 minutes. 4 large egg whites 1 cup (200 g) granulated sugar ½ teaspoon cream of tartar
• Whip egg whites. Transfer bowl to electric mixer fitted with the whisk attachment, and beat, starting on low speed, gradually increasing to high, until stiff, glossy peaks form, 5 to 7 minutes. Add vanilla, and mix until combined. Use immediately. 1 teaspoon vanilla extract
• Spread frosting on top of cooled brownies.
• Using a kitchen torch, lightly brown the frosting. Or you can place into an oven on broil setting and broil for 1 to 2 minutes.