Preheat oven to 350 degrees F and grease a half sheet.
In the bowl of a stand mixer fitted with the paddle attachment, combine flour, baking powder, eggs, sugar, and soft butter. Mix until a crumbly dough forms.
Empty dough out onto a clingfilm-covered workspace and press into a ball. Roll out between cling film. Transfer to baking sheet press into edges.
In the same bowl, mix together greek yogurt, sugar, eggs, oil, vanilla pudding, corn starch, and milk until smooth. Pour over crust and smooth out.
Evenly distribute mandarin oranges over the mixture.
Bake for 45-55 minutes until edges are lightly browned. Let cool before slicing and serving!