For the frosting, beat cream cheese and butter in a large bowl until smooth using an electric mixer. Scrape down the sides of the bowl. Beat in sugar, then jam.

In a separate, chilled bowl, beat heavy cream until stiff peaks form. Fold whipped cream into frosting. Cover and chill for a couple of hours.

Preheat the oven to 325 degrees F. Butter and flour three 9-inch round cake pans.

In a medium bowl whisk together flour, salt, baking powder, and baking soda. In a large bowl, cream butter and sugar together until light and fluffy. Add eggs one at a time, beating after each addition. Beat in vanilla and sour cream.

Add flour mixture in three additions, beating to blend after each addition. Divide batter into prepared pans.

Bake until a toothpick inserted into the center comes out clean, about 35-40 minutes. Cool for 10 minutes.

Run a knife around the edges, then turn cakes out onto a rack to cool completely.

Slice off any domed tops of the cake. Place one half bottom-side up on a cake plate. Spread 2 tablespoons of strawberry jam over the cake, then spread ¾ cup of frosting, followed by ¾ cup of sliced strawberries in a single layer. Repeat for the next layers.

Top with remaining cake layer. Spread two cups of frosting over the top and sides in a thin layer, then frost with remaining frosting. Spoon teaspoonfuls of remaining jam onto the cake and swirl decoratively.

Chill if the cake won't be cut for more than an hour.