This is my late mother's recipe. Everyone loves it, even those who say they hate rhubarb. When made as a pie I use a lattice crust top but this is so flavorful I make it as a tart. Many years ago I took this to a picnic at my boss's house. His father was there and ate a piece of my tart. Although, he stated he hated rhubarb he exclaimed after his first bite "I don't know what rhubarb pie you ate, but this is the best d***** apple pie I have ever tasted! —Susan52
Preheat oven to 375 degrees
Line tart pan with pie crust
Combine sugar, cinnamon, flour, eggs and mix well.
Add cut rhubarb, mix and pour into unbaked tart crust.
Top tart with small pieces of butter.
Put tart on a lined baking sheet to prevent spills.
Bake tart 50 minutes or until done.
Cool before serving.