How to Make It
In a bowl, beat the butter with the fleur de sel until fluffy, about 3 minutes.
Line a baking sheet with parchment paper. In a large bowl, sift the 2 1/4 cups of flour with the sugar, baking powder and salt. Using your fingertips, rub the butter into the flour mixture until it resembles coarse crumbs. Add the dates and toss to coat in flour. Drizzle in the 1 1/2 cups of cream and stir until a dough forms. Cover with plastic wrap and let stand for 10 minutes.
Turn the dough out onto a lightly floured work surface and knead gently until it comes together. Pat the dough into a 5-by-10-inch rectangle. Cut into 8 equal squares and arrange on the prepared sheet. Refrigerate for 30 minutes.
Preheat the oven to 375°. Brush the tops of the scones with cream and sprinkle with turbinado sugar. Bake for about 25 minutes, until golden. Transfer the scones to a rack to cool completely. Serve with the salted whipped butter and jam.