Lightly grease a 9x5-inch loaf pan and line it with plastic wrap. Slice the pound cake into ½-inch slices and arrange them in a single layer on the bottom and up the sides, pressing to fill gaps.

Scoop half of the softened ice cream over the cake and spread it into an even layer. Scatter half of the sliced strawberries on top.

Spread the strawberry jam over the berries, then spoon the remaining ice cream on top and smooth it. Whip the heavy cream, powdered sugar, and vanilla to soft peaks, then spread over the top.

Cover the cake with plastic wrap and freeze until solid, at least 6 hours. To serve, lift the cake out using the plastic, peel off the wrap, and slice into slabs.