- Portion size 12 servings
Line 17- x 11-inch (45 x 29 cm) rimmed baking sheet with parchment paper; set aside.
In large bowl, beat egg yolks with half of the sugar until pale and thickened, about 5 minutes; beat in vanilla. In separate bowl, sift together flour, all but 1 tbsp (15 mL) of the cocoa, and salt. Sift again if necessary to blend cocoa and flour completely. Set bowls aside.
In third bowl, beat egg whites until soft peaks form; beat in remaining sugar, 2 tbsp (25 mL) at time, until stiff peaks form. Spoon one-third over egg yolk mixture; sift one-third of the flour mixture over top and fold in. Repeat twice with remaining egg white and flour mixtures.
Spread in prepared pan. Bake in centre of 400°F (200°C) oven until cake springs back when lightly touched, about 12 minutes. Run knife around edge of pan to loosen cake; let cool in pan on rack for 2 minutes. Dust clean tea towel with remaining cocoa. Invert cake onto towel; peel off paper. Starting at 1 long side, roll up cake in towel. Let cool on rack.
Meanwhile, transfer ice cream to refrigerator to soften until spreadable, about 20 minutes. Unroll cake; trim edges. Leaving 1-inch (2.5 cm) border along 1 long side, spread lightly with raspberry jam, then ice cream. Starting at opposite side, reroll gently but firmly. Wrap in plastic wrap and place, seam side down, in large airtight container. Freeze until firm, about 12 hours. (Make-ahead: Freeze for up to 2 weeks.)
Unwrap; transfer to chilled serving platter. Using fine sieve, dust with icing sugar. Garnish with fruit. Cut into slices to serve.