Use room temperature cream cheese.
Beat cream cheese until fluffy Add vanilla and lemon rind.
Mix together flour, sugar, salt. Blend into cream cheese mixture.
Beat in eggs and yolks, one at a time.
Pour into prepared pan. Bake for 8-10 minutes.
Reduce oven to 200 degrees. Bake for one hour or until set.
Turn oven off. Keep cheese cake in oven with door open.
Cool on a rack.
Chill before serving.
You can pour blackberry sauce over entire top of cheesecake or on individual servings. Serve with a few whole blackberries for garnish.