Preheat oven to 350°F.
Combine flour and sugars. Cut in butter until mixture resembles coarse crumbs. Stir in oats and nuts. Reserve 1 cup. Press remaining crumb mixture onto bottom of a greased 13x 9-inch baking pan.
Combine cream cheese and egg, mixing until well blended. Add lemon juice, blending well. Spread evenly over crust mixture; sprinkle with reserved crumb mixture.
Bake for 25-30 minutes or until golden brown. Cool. Cut into bars.