A salty and sweet treat great for sharing!
On a lightly floured surface, roll the two pie shells together into an 11-inch circle. Fit into a 9-inch tart pan with a removable bottom (alternatively, use one of the pie shells as is). Prick all over with a fork and blind-bake until golden following the package instructions (becuase the crust is thicker, this could take up to 10 min longer than the package bake time suggests) Cool completely.
Combine sugar, water and corn syrup in a medium saucepan over medium high heat, brushing down the sides occasionally with a wet brush until the mixture is a deep amber colour, about 12 minutes. Remove from heat and quickly whisk in cream, butter and salt until smooth. Pour into cooled shell and let sit for one hour to set.
In a bowl fitted over a saucepan of simmering water, melt chocolate with cream, stirring often, until smooth. Stir in butter until combined and glossy. Poured over cooled caramel and refrigerate until set, about 1 hour. (Let it set at room temperature for 2 hours if you’d prefer a runny caramel). Sprinkle with sea salt just before serving.