Jenny's Birthday Chocolate Swiss Roll

Step 1
Preheat the oven to 375 degrees F (190 degrees C). Line all sides of a 17x12x1-inch baking pan with aluminum foil. Spray with cooking spray.

Step 2
Stir 1 cup plus 2 tablespoons flour, cocoa, baking powder, and salt together in a bowl. Set aside.

Step 3
Beat eggs in a large mixing bowl using an electric mixer until very thick and lemon-colored, about 5 minutes. Gradually beat in white sugar until combined. Blend water and vanilla extract into mixture on low speed until combined.

Step 4
Gradually sift flour mixture into egg mixture, beating just until batter is smooth. Pour batter into the prepared pan, spreading to corners.

Step 5
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 12 to 15 minutes.

Step 6
Cover a tray or pan with a paper towel and sprinkle it with confectioners' sugar. Loosen cake from the edges of the baking pan and carefully invert onto the sugared paper towel; cake will be bottom-side up. Carefully remove the aluminum foil from cake bottom, trimming off stiff edges if necessary.

Step 7
Roll cake from the narrow end while hot, bottom-side out, including paper towel. Cool completely on a wire rack, about 30 minutes.

Step 8
Unroll cake and remove the paper towel.

Step 9
Whip heavy cream in a large bowl using an electric mixer until stiff peaks are just about to form. Beat in confectioners' sugar and vanilla extract until peaks form, making sure not to overbeat as cream will become lumpy and butter-like.

Step 10
Spread whipped cream over cooled cake. Roll cake back up and sprinkle with 1 tablespoon confectioners' sugar.