Preheat oven to 350 degrees F. Line an 8 inch square metal pan with foil and spray foil with cooking/baking spray (or just use nonstick foil).
Pulse flour, sugar and salt in food processor to mix. Add butter and pulse until mixture has the consistency of cornmeal. Add orange zest and pulse once or twice more. Measure out 1/2 cup and set aside. Dump remainder into pan and press into bottom. Bake for 12 minutes or until lightly browned.
Meanwhile, wipe out food processor or switch bowls.
Process cream cheese and sugar until creamy. Add lemon juice and vanilla and process another 30 seconds, scraping sides. Add egg and process for another 30 seconds. Add pineapple and pulse just until mixed. Pour this mixture over baked crust and spread to ends. Sprinkle reserved crumb mixture over top. Return to oven and bake for another 15 minutes. Let cool completely, then chill for at least two hours.
Grasp foil, lift bars from pan and cut into squares.