In a large bowl mix together the flour, sugar, baking powder, and salt.

Add the butter to the flour mixture. Using your hands mix the butter into
the dough until it resembles coarse, wet sand.  Set aside. 

In a small bowl combine the egg, sour cream, milk, lemon juice, and vanilla. 

Add to the flour mixture and mix until the ingredients are just combined.

Turn the dough onto a floured surface. Shape into 2 half inch thick circles. 

Place one circle on a cutting board. Spread the jam on the circle leaving a small 1/2 inch without jam on the outer edge.

Carefully place the other circle on top of the jam and pinch the edges closed.

Using a sharp knife or pizza cutter cut the dough into 8 pieces. 

Place the scones on a baking sheet 2-3 inches apart.  Brush the tops of each scone with milk and sprinkle with coarse sugar if desired.

Bake for 20-22 minutes or until they are golden brown.

Cool completely on a wire rack.