Preheat oven to 325 degrees F (165 degrees C). Grease a 10 inch Bundt pan or line a muffin pan with paper cups.
In a medium bowl, stir together the cake mix and instant pudding. Add the tangerine juice, oil, eggs and lemon extract, mix until well blended. Pour into the prepared pan or pans.
Bake for 35 to 40 minutes in the preheated oven, until the cake springs back to the touch. For cupcakes, bake for 15 to 17 minutes. Let cool in the pan for 10 minutes before removing from pan to cool completely.
In a small saucepan, combine the remaining tangerine juice, sugar and butter over medium heat. Stir frequently until the mixture is smooth. Drizzle over cooled cake or cupcakes.