Celebration Red Velvet Roll Cake

1Preheat oven to 350˚F (180˚C). Line two 15 x 10 x 1-in. (38 x 25 x 2.5-cm) baking sheets with parchment paper. In bowl, sift together flour, cocoa powder, baking powder, baking soda and salt; set aside. In small measuring cup, combine milk, red food colouring and oil. Set aside.

2In large bowl, use electric hand-mixer to beat the 8 egg whites to soft peaks, about 2 min. With the mixer on low speed, gradually beat in 1 cup (250 mL) sugar. Set aside. In separate bowl, beat the 8 egg yolks and vanilla. Gradually beat in remaining 1/2 cup (125 mL) sugar until mixture is pale yellow, 2 to 3 min. With the mixer on low speed, beat in flour mixture in thirds, alternating with 2 additions of milk mixture, finishing with the flour mixture. Scrape down the batter in the bowl as needed. Gently fold beaten egg whites into batter.

3Divide batter between prepared baking sheets, smoothing tops. Bake on middle rack 12 to 15 min., until a tester inserted in centre of cakes comes out clean. Cool cakes in baking sheet 1 min. on wire rack. Use knife to loosen edges of cake from baking sheet. Dust 2 clean, lint-free tea towels with icing sugar. Place over cakes, with 2-in. (5-cm) towel overhang on the short side of the cake. Place a board (larger than baking sheet) on top of tea towel. Holding all layers, invert cake, sheet, towel and board. Remove the board and baking sheet. Gently peel off parchment paper from cake. Starting with short side, pick up edge of tea towel and roll up cake into a log with the tea towel inside separating the layers of cake. Repeat with second sheet cake. Leave cakes inside rolled towels to cool completely on wire rack,
about 30 min.

4Meanwhile, to make meringue icing, in large heatproof bowl, whisk together sugar, 1/4 cup (60 mL) water, 4 egg whites, cream of tartar and salt. Set bowl over saucepan of barely simmering water and beat with electric hand mixer -- fitted with clean beaters -- until mixture holds stiff peaks, about 7 min. Remove from heat and continue to beat until cooled. Set aside. Carefully, unroll cakes and remove towels. Immediately spread 1 cup (250 mL) icing over each cooled cake. Starting at the short end, roll up one cake. Place the roll onto the second cake -- matching up seams. Roll up second cake around first one to form one large jelly roll. Transfer cake seam side-down onto unlined baking sheet. Spread remaining icing on sides of roll, leaving ends un-iced.

5Preheat oven to broil. Broil cake about 2 min., rotating pan halfway through for even browning of meringue. Watch carefully to avoid burning. Remove cake from oven. Using 2 cake spatulas, carefully transfer to a serving platter or board. Arrange berries and grapes around cake to serve.