I won’t get into the runny vs. firm controversy here, except to say that I want to eat my butter tart, not wear it. These tarts are very fine indeed. The filling is silky, yet covered by a thin, slightly chewy crust. The recipe, however, can satisfy both camps: For a runnier, silkier filling, stick to the lower end of the baking time and enjoy the tarts slightly warm; for a slightly firmer, chewier filling, go to the higher end and/or eat them the next day.
You could cheat for speed with store-bought tart shells. However, I put the tarts over the top by making rich, tender, crumbly shells with a soft pâte brisée. Prepare the dough in advance and keep it cold. Once the filling is set aside to cool, you should have enough time to roll and cut the dough, place the rounds in muffin tins, then stash the lot in the fridge to firm up.
1 cup (250 mL) corn syrup
2/3 cup (160 mL) packed dark brown sugar
2 large eggs
1/2 tsp (2 mL) vanilla extract
1/4 tsp (1 mL) salt
1/4 cup (60 mL) cold, unsalted butter, cut in 20 bits
15 cold, uncooked, 3 inch (7.5 cm) tart shells
Stir together syrup and sugar in medium pan. Cook on medium heat, stirring twice, until mixture bubbles up and top is covered with foam. Immediately reduce heat to low and simmer 5 minutes. Remove from heat. Cool 2 minutes.
Meanwhile, in heatproof bowl, whisk eggs lightly with vanilla and salt. While whisking constantly, slowly pour in syrup mixture. Add butter and stir until melted. Cool to room temperature, about 30 minutes.
Fill each tart shell about two-thirds full. Bake in preheated 450F (230C) oven 5 minutes. Reduce heat to 350F (180C). Bake until pastry is golden and filling is puffy but not too dark, about 10 minutes (for runnier tarts) to 15 minutes (for firmer tarts).
Credit: Susan Sampson
Tested in Imperial