Preheat your oven to 350°F (175°C) and prepare a jelly roll pan (10x15 inches) by lightly spraying with baking spray and lining with parchment paper.

In a large bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.

In another bowl, combine the egg yolks, 1/2 cup granulated sugar, brown sugar, melted butter, and vanilla extract. Whisk until light and fluffy.

Add the flour mixture to the egg yolk mixture and stir until combined.

In a clean bowl, beat the egg whites until soft peaks form. Gradually add the remaining granulated sugar and beat until stiff peaks form.

Gently fold the egg whites into the chocolate mixture until smooth.

Spread the batter evenly in the prepared pan and bake for 15-18 minutes until it springs back gently to touch.

Dust a kitchen towel with cocoa powder while the cake is baking.

Once baked, let the cake rest for 2 minutes, then invert it onto the prepared towel and remove the parchment paper.

Roll the cake up in the towel and let it cool completely.

Prepare your filling of choice, such as Ermine icing or whipped cream.

Once the cake is cool, unroll it carefully and spread the filling evenly before rolling it back into a log.

Transfer the roll to a wax-paper lined platter and refrigerate.

For the glaze, combine melted chocolate chips and shortening in a heatproof bowl. Microwave until melted, then pour over the roll.

Refrigerate until the glaze hardens, then slice and serve.