Line a 9- by 5-inch loaf pan with plastic wrap.

Combine eggs, sugar, and vanilla in a heat-proof bowl and set over a pan of simmering water, making sure the bottom of the bowl does not touch the water. Beat with a hand-held mixer (or whisk by hand) for 5 minutes. The mixture should be light and frothy. Remove from heat and continue to beat until thick and pale, about 2 minutes.

Whip the cream until soft peaks form.

Line the bottom of the pan with an even layer of frozen berries. Lightly mash the remaining frozen berries, then fold into the egg mixture. Fold the cream into the egg mixture. Pour into the prepared pan on top of the berries, smooth the top, wrap with foil, and freeze overnight.

To serve, remove foil, invert on a serving platter, remove the pan and plastic wrap, top with fresh berries, sprinkle with powdered sugar, and garnish with mint.