Separate eggs. Beat whites with a pinch of salt, gradually adding half the sugar (65 grams), until stiff and glossy, about 7 minutes. Whisk yolks with remaining sugar (65 grams) until pale and thick. Fold yolks into whites until smooth, then sift in flour and cornstarch and fold to combine. Transfer to a piping bag fitted with a round tip and pipe 4-centimeter/1½-inch lengths. Dust generously with powdered sugar and bake until lightly golden, about 12 minutes. Cool completely.

Whisk egg yolks and sugar for the zabaglione in a heatproof bowl for 3 minutes. Set over a double boiler and whisk constantly until the sugar dissolves and the mixture thickens slightly. For pasteurization, heat to 150°F/65°C. Stir in Marsala or coffee liqueur.

Stir mascarpone and vanilla until smooth. Fold in the warm yolk mixture in two additions until fully incorporated and silky.

Dip ladyfingers quickly in espresso and arrange a single layer in a serving dish. Spread half the cream evenly over the top. Repeat with a second layer of dipped ladyfingers and remaining cream, smoothing the surface. Cover and refrigerate at least 6 hours or overnight. Dust with cocoa powder just before serving.