Using your hands cut the medjool dates in half and remove the pits, place dates cut side down onto cooled tart shell, in a circular formation. Whisk egg yolks, sugar, heavy cream, vanilla and salt until smooth. Pour the custard mix over the dates and slowly transfer the tart back into the oven and bake at 350 degrees F for 25-30 minutes or until the edges are completely set but the middle is still somewhat jiggly. Allow the tart shell to completely cool down at room temperature.