In a medium bowl, stir together the oats, nuts, brown sugar and cinnamon. Add melted butter and stir until well combined. Press evenly into the bottom of a greased 9-inch springform pan. Bake at 350F for 18-20 minutes or until light brown. Set aside to cool. In a large bowl, combine cream cheese, brown sugar, corn syrup and corn starch. Beat with mixer until smooth. Add eggs, and egg yolk, one at time, beating well after each addition. Stir in vanilla extract. Pour mixture over crust. Bake at 350F for 15 minutes. Lower the temperature to 225F and bake for 40 minutes. Sprinkle the chocolate chips over top of cake and bake for 35 minutes or until the top no longer looks wet or shiny. Remove cake from oven and run a knife around the inside edge of pan. Turn oven off; return the cake to the oven for an additional hour. Chill, uncovered overnight. ----