Step 1

Preheat the oven to 350°F. Line a 9 1/2" x 14" jelly roll pan with parchment paper and spray with non-stick vegetable oil spray., To make the cake: In a large bowl, beat the eggs until thick and pale, then beat in the sugar, salt, and extracts., Sift together the flour, cocoa, and baking powder, and fold gently into the egg mixture. Whisk together the oil and buttermilk and fold in, stirring just until combined., Spread the batter onto the pan and smooth with a spatula. Bake the cake for 10 to 12 minutes, until the top springs back when pressed gently., Remove the cake from the oven, let it cool in the pan for 1 to 2 minutes, then loosen the edges with knife. Turn out onto a tea towel lightly dusted with confectioners' sugar (or onto a piece of parchment), roll up loosely (starting with a short end), and let cool completely., To make the filling: Stir together the cream and vanilla extract in a large mixing bowl. Mix together the sugar and ClearJel in a small bowl and sprinkle over the cream. Whip the cream (by hand, stand mixer, or hand mixer) until soft peaks form then fold in the finely ground chocolate or sweet ground chocolate. Refrigerate until needed., To make the glaze: Gently heat all of the ingredients until the chocolate is melted and the mixture is smooth. Cool for 10 to 15 minutes to thicken slightly., To finish the cake: Unroll the cake and spread it with the filling. Re-roll, and place seam-side down on rack set over a piece of parchment or wax paper. Trim the ends for a clean appearance., Pour the chocolate glaze over the cake, spreading it to cover the ends and sides and allowing the excess to drip onto the paper below. Allow the glaze to set for 10 to 15 minutes, then if desired pour the excess glaze back over the cake.

Step 2

, Serve the cake immediately, or refrigerate until ready to serve, up to 24 hours. Freeze for longer storage.