Chocolate Swiss Roll Cake with Toasted Marshmallow Frosting

Instructions

For the Cake:

1. Preheat oven to 350 degrees F. Grease a 10 1/2-by-15 1/2-by-1-inch jellyroll pan and line with parchment; grease paper.
2. In a medium bowl sift together flour, cocoa, graham cracker crumbs, and baking soda twice. (Discard the bigger pieces of graham cracker that doesn't pass through your sieve.)
3. In a small saucepan over low heat, melt butter. Remove the white foam on top of the butter, and pour clear yellow butter into a bowl, making sure to discard the white liquid at the bottom.
4. In a medium bowl, using an electric mixer whisk together eggs and sugar, on medium-high heat about 3 to 4 minutes or until the mixture is thick, pale and tripled in size. Reduce the speed to medium and beat in the vanilla extracts for an additional 2 to 3 minutes.
5. Using a spatula, gently fold in the sifted flour mixture in three additions. During the last addition, drizzle the melted butter over the batter and fold in. The batter will be thin. Spread evenly in prepared pan. Tap the pan on the counter to remove any air bubbles. Bake the cake until it springs back when touched in the center, about 15-20 minutes. Try not to over-bake, or the cake will crack. While the cake is baking, generously dust a tea/dish towel with powdered sugar.
6. Dust cake with powdered sugar. Invert cake onto the tea towel and peel off parchment. Dust with powdered sugar. Starting at the longest end, carefully roll up cake in towel. Allow cake to cool on a cooling rack seam side down.

Toasted Marshmallow Filling:

1. Preheat oven to broil.
2. Line a cookie sheet with foil and spray with nonstick cooking spray.
3. Place the marshmallows on the lined sheet and place it on the lowest rack of the oven.
4. Broil marshmallows until brown, about 30-60 seconds. Keep an eye on them as they burn really fast.
5. Remove pan from oven and turn the marshmallows over.
6. Broil until golden brown, another 30-60 seconds.
7. In an electric mixer fitted with the paddle attachment, beat the butter and powdered sugar on low until combined, about 1 minute. Add vanilla and increase speed to medium and beat for about 3 minutes.
8. Add the toasted marshmallows and mix on the lowest speed for 1 minute, just until combined.

To Assemble:

1. Unroll the cake and spread the buttercream filling leaving a ¼ inch in thickness around the edges. Roll up the filled cake carefully from end to end. Trim off the edges for a cleaner finish.
2. Transfer the cake to a serving plate. Top with additional toasted marshmallows. Sprinkle with crushed graham crackers if using.