Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius). Use baking spray to spray bottom of a 9-inch (23-cm) springform pan with 2½-inch (6½-cm)-high sides. Wrap the outside of the pan with three layers of heavy-duty foil.

Place tea biscuits in food processer and process till the cookies are well ground. Add all ingredients except for the melted butter and pulse a few more seconds.

Combine ground cookie mixture and butter in a medium-sized bowl until moist clumps form. Press cookie mixture firmly into the bottom of the prepared pan. Bake crust until firm and beginning to darken, about 14 minutes. Cool.

Beat cream cheese and sugar in a large bowl until smooth. Beat in butter and then eggs, one at a time, until just blended. Beat in vanilla.

Pour the batter over crust in pan.

Place springform pan in a large roasting pan. Add enough hot water to come halfway up the sides of the springform pan. Bake uncovered until the filling is puffed and moves slightly when pan is shaken, about 1 hour and 10 minutes.

Remove pan from water and remove foil. Place hot cheesecake uncovered in the refrigerator overnight.

Combine sugar, water, and lemon juice in large saucepan over medium heat until sugar dissolves.

Raise heat and boil without stirring until mixture turns a deep amber color, occasionally swirling the pan and brushing down the sides with a wet pastry brush, about 9 minutes.

Add cream (mixture will bubble).

Reduce heat to medium-low and simmer until reduced to 1¼ cups, stirring occasionally until thickened but still pourable, about 15 minutes.

Spoon caramel sauce over top of the cake, just to the edge. (Do not allow to drip down sides.)

Garnish top edges with chopped Viennese crunch or praline crunch. Chill cake for at least 2 hours.

Run knife around pan sides to loosen cake and release springform.