I made this yesterday to take to church this morning for the guys to have a little breakfast treat during their praise team practice. I'm happy to say I came home with an empty container. I personally like it best after a little refrigeration time...the jam and cream cheese firmed up and the flavors melded together nicely. It was even better today than it was yesterday. I would imagine raspberry or cherry jam would be great too!
For streusel, combine brown sugar, flour and oats in medium bowl. Cut in butter with pastry blender or with fingers to form course crumbs. (I pulse this in a small mini chopper). Stir in nuts if desired. Refrigerate until time to use.
For the filling, in a mixing bowl beat cream cheese until creamy. Add sugar and flour and beat until well mixed. Blend in vanilla extract and egg. Stir in sour cream. Set aside.
For the cake batter, cream together butter, sugar and vanilla. Add eggs, beating well after each addition. In a separate bowl, combine the flour, baking powder, and baking soda. Add the dry ingredients to the butter mixture alternately with the sour cream. Spread the batter evenly into a greased 9" square pan (or 8"..a little more cooking time may need to be added).
Carefully spread cream cheese filling over the batter, leaving about a 1/4" border around the edges. Drop teaspoons of jam/preserves onto the cream cheese filling. I used almost a 1/2 cup.
Evenly top with the streusel topping. Bake at 350 degrees for 30 to 40 minutes or until a toothpick inserted into the center comes out clean (jam may be on the tooth pick but that's okay...as long as it isn't actual cake batter). It took exactly 35 minutes in my oven.
Let cool on wire rack for 30 minutes. While it is cooling, prepare the glaze by stirring 1 - 2 tablespoons of strawberry jam into the powdered sugar. If it's too thick, add a little milk. Drizzle over the cake. Refrigerate to allow the cream cheese and jam to firm up.