Spray a 10×15 inch baking pan with nonstick spray, line the pan with parchment paper, spray again, then lightly dust with cocoa powder.
In a mixer with a whisk attachment, beat the egg whites and ¼ cup of sugar on high speed for 5 minutes, or until stiff peaks form. Set aside.
In a new bowl, whisk together the egg yolks and remaining ¼ cup of sugar for 2-3 minutes, or until egg yolks are frothy. Add the canola oil, vanilla extract, and espresso powder then whisk until combined.
In a new bowl, sift together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
Mix the dry ingredients with the egg yolk mixture until well combined.
Gently fold in ⅓ of the egg white mixture. Add in the remaining egg white mixture, gently folding until batter is combined, being careful not to overmix.
Spread batter into the 10×15 pan and bake for 10 minutes or until the top of the cake gently springs back.
Note: Do not over bake, as this will impact cracking while rolling.
As the cake is baking, place a piece of parchment paper on a clean, flat surface and lightly dust with cocoa powder. Remove the cake from the oven and run a knife around the edges to gently release. Immediately invert the cake onto the new parchment paper. Peel off the old parchment paper from the bottom, then slowly roll the warm cake with the new parchment and let it cool for 1-2 hours.
Allow the ice cream to sit at room temperature to soften for 20 minutes. Line a 13×9 baking pan with parchment paper and evenly spread the Mint Chip ice cream in the pan. Place in the freezer to harden for 2+ hours.
Once completely cooled, slowly unroll the cake and invert the prepared ice cream pan onto the cake, leaving a ½ inch border around the cake. Gently roll the cake up again and place into the freezer.
Place the chopped chocolate in a medium bowl. Heat the heavy cream on the stovetop until small bubbles start to form on the outer edge in the pan. Pour the warm cream over the chocolate and allow it to sit for 5 minutes. Whisk until the chocolate is melted.
Pour the chocolate over the cake, slice and serve.