LEMON-LIME BARS ~ for Type Os

For the crust:
    3/4 lb. unsalted butter, at room temperature
    3/4 cup granulated sugar
    3 cup spelt flour
    1/4 tsp. kosher salt

For the filling:
    6 large eggs, at room temperature
    3 cups granulated sugar
    1 Tbsp. finely grated Meyer lemon zest
    1 Tbsp. finely grated lime zest
    1 cup freshly squeezed lemon/lime juice (I used 6 small Meyer lemons and 2 limes)
    1 cup spelt flour
    Confectioners' sugar, for dusting (click here for Type-O acceptable for recipe)

Butter a 9 x 13 x 2" baking pan, then line the bottom and sides of the pan with parchment paper. This is optional but will make removing the bars from the pan, much simpler.

For the crust: Cream the butter and sugar until light in the bowl of an electric mixer fitted with the paddle attachment.

Combine the flour and salt and, with the mixer on low, add to the butter mixture until just mixed.

Dump the dough onto a well-floured board and gather into a ball. Flatten the dough with floured hands and press it into the bottom of prepared pan.

Chill the pan while the oven preheats to 350° F.

Bake the crust for 15 to 20 minutes, until very lightly browned. Let cool on a wire rack. Leave the oven on.

For the filling: Whisk together the eggs, sugar, lemon and lime zest, lemon and lime juice, and flour.

Pour over the crust and bake for 35-45 minutes, until filling is set.

Let cool to room temperature. Cut into squares or triangles and dust with confectioners' sugar.

Store any leftovers in a covered container in the refrigerator.

Makes about 24 squares.

Adapted from recipe at: http://lickthebowlgood.blogspot.com/2011/03/best-ive-ever-had.html