Sweet Potato Cheesecake Bars

Name: Sweet Potato Cheesecake Bars
Prep time: 15 min
Cook time: 2 h
Total time: 2 h
Yield: 20 piece
Ingredients: 80 - 90 gram sugar; 80 gram butter, unsalted (from cows' milk); 150 gram wheat flour; 1 egg, European medium (53-63 g) (from chicken); 20 gram cocoa powder, unsweetened; ½ teaspoon baking powder; 1 - 2 pinch salt; 600 gram water; 300 gram sweet potato; 3 egg yolk (from chicken egg); 500 gram ricotta cheese, fresh; 200 gram cream cheese; 140 - 100 gram condensed milk, sweetened; 20 gram cornflour (starch); 1 teaspoon vanilla extract, natural; 60 gram condensed milk, sweetened