For the frosting beat cream cheese and butter in a large bowl until smooth. You will want to use a electric mixer so you don't end up with lumps. Stop every now and then to scrape down the sides of the bowl.
Beat in sugar then jam. Beat cream in a separate chilled bowl until peaks form. Fold whipped cream into frosting. Cover and chill for a couple of hours until its firm enough to spread.
For the cake preheat oven to 325. Butter and flour 2-9 inch cake pans with 2 inch high sides. In a medium bowl whist together flour, salt, baking powder and baking soda.
In a large bowl cream butter and sugar together until light and fluffy. Add eggs 1 at a time beating after each addition.
Beat in vanilla. Add sour cream and beat for 30 seconds. Add flour mixture in 3 additions beating to blend after each addition. Divide batter into prepared pans.
Bake cake until a toothpick inserted into the center comes out clean 50-60 minutes. Remove from oven and cool for 10 minutes.
Run a sharp knife around the edges of the pans then turn cakes out onto a rack to cool completely. You may want to refrigerate them for a couple of hours to make the next step easier.
Using a serrated knife divide each layer in half horizontally. Place each half cake side down on a cake plate. Spread 2 tablespoons strawberry jam over the cake then spread 3/4 cup of the frosting over the jam.
Arrange 3/4 of the sliced strawberries on top of the frosting in a single layer. Repeat 2 more times with cake layer, jam, frosting and strawberries. Top with remaining cake layer cut side down.
Spread 2 cups of frosting over the top and sides of the cake in a thin layer then frost with remaining frosting.
Stir remaining jam to loosen then spoon teaspoonfuls onto the top and sides of the cake. Use the back of a spoon to swirl jam decoratively into the frosting.