The name implies simplicity, but has more to do with the ratio of sugar, butter, and flour by weight. I like using sweet dough for two reasons: ease of use, as it is less prone to shrinkage, and taste, especially with fillings that are not overly sweet. This makes enough for 2 pie shells or about 18 individual tart shells

270 g flour (9oz)
90 g sugar (3 oz)
180 g butter, cut into small pieces (6 oz)
2 ml salt (1/2 tsp
1 egg
5 ml vanilla extract (1 tsp)

Combine flour, sugar, and salt
Add butter and work in until mealy
Beat egg with vanilla and add to flour mixture
Knead lightly until combined
Divide into two halves and pat each into a thick disc
Wrap and refrigerate for at least 1/2 hour

To make a pre-baked shell:

Roll out and line a pie or tart shell
Dock and trim edges
Chill until cold
Line with parchment paper and weigh down with rice or dry beans
Bake in a 350 F oven for 30 minutes, or until golden brown around edges
Remove parchment and weights and return to oven for 5 minutes to colour centre lightly
Cool to room temperature
Use as directed in recipe