To prepare the crust, combine the first 3 ingredients in a bowl, and toss with a fork until moist. Firmly press the mixture into the bottom of a 9-inch springform pan.
To prepare filling, beat cocoa and milk at medium speed of a mixer until blended. Add cream cheese; beat well. Add syrup, extracts, and eggs; beat just until smooth. Pour mixture into prepared crust. Bake at 350° for 35 minutes or until set. (Do not overbake.) Cool completely on a wire rack. Cover and chill 4 hours.
To prepare topping, shave long edge of mint thins using a vegetable peeler. Spread whipped topping over tart; sprinkle with shaved mint thins.