I think that a cool way to make the tart shells would be to make the shells as if one were making sandbakkel tarts. Here's a link to a recipe that is close to my grandma's. Since you are making butter tarts, I'd probably use pecans and omit the almond extract.
The trick to getting the dough in those molds (the ones shown) is to roll the chilled dough in 3 small balls, about the size of a cherry, and then press into the molds with your thumbs. Prick them before you bake them, and take them out before they brown. To fill them, I'd suggest baking for about 2-3 minutes, remove from oven, fill, and then bake until the filling is set. That would be the experiment I would try. But, if you are putting the dough into tart molds, I'd suggest lightly greasing the molds (we wack the sandbakkler molds on a bread board and flip them...I doubt you want to wack them if you had filling in them).
Regardless of the recipe you use to make the tart base, I'd try rolling the dough in little balls and pressing it into your tart molds or muffin pan (I have lots of recipes for butter tarts--a Canadian favorite--where they are baked in muffin tins).