Instructions

1. Cake: Preheat oven to 375F.
2. Grease a 15x10-inch sheet cake pan or jelly roll pan. Line pan with parchment paper, then grease and flour parchment.
3. In a large bowl, mix together flour, cocoa, baking powder, baking soda and salt.
4. Using a stand mixer, add egg whites and beat until soft peaks form. Gradually add 1/2 cup granulated sugar, beating until stiff peaks form. Pour into bowl. Set mixture aside.
5. In a separate mixing bowl, using a stand mixer with clean paddle attachment, combine egg yolks and vanilla. Beat on medium speed for 3 minutes. Gradually add remaining 1/3 cup granulated sugar and continue beating for 2 additional minutes.
6. Add cocoa mixture to egg yolk mixture and beat on low speed, slowly adding water and mixing until batter is smooth.
7. Gradually fold chocolate mixture into beaten egg whites until ingredients are well-blended.
8. Spread batter evenly in prepared baking pan.
9. Bake for 14 to 16 minutes or until top springs back when touched lightly in the center and a toothpick inserted comes out clean.
10. Allow cake to cool in pan for about 1 minute.
11. Carefully, lift parchment paper and hot cake out of the pan and onto a cutting board.
12. Immediately, starting at one of the short ends of the cake, use hands to gently and slowly roll cake -- and parchment paper -- all the way up.
13. Place cake on wire rack and allow the rolled up cake to cool completely.
14. Transfer to refrigerator to cool for an additional 30 minutes.
15. Filling: In a clean mixing bowl, combine cream cheese, butter,  powdered sugar and peppermint extract. Beat until fluffy and smooth.
16. Gently stir in crushed peppermint candies, to taste. Save a handful of crushed candies for garnishing the finished cake.
17. Once the cake roll is cooled completely, unroll it very carefully.
18. Gently smooth filling in an even layer over the cake.
19. Roll up the cake, without parchment paper. If you see it start to stick at all to the paper, use a metal knife to scrape along the bottom edge of the cake as you roll it up to help release it.
20. Cover cake with plastic wrap and refrigerate for at least 1 hour.
21. Ganache: In a saucepan, over medium-high heat, heat heavy cream until hot.
22. Place chocolate chips in a bowl. Pour hot cream over chocolate chips and stir continuously until chocolate is melted and smooth.
23. Allow ganache to cool for several minutes to give it time to thicken up a little.
24. Pour chocolate ganache over top of peppermint roll. Sprinkle additional chopped peppermint candy on top.
25. Refrigerate for at least 20 minutes before serving.
26. Slice and serve.

Note: The cake can be stored in the refrigerator, covered, for up to 3 days.