At least 8 hours, or one day before baking, make the dough.

Line a baking sheet with parchment paper and set aside.

In a medium bowl, combine the flour, baking powder and salt and whisk together for 30 seconds.

In a large bowl, using an electric mixer set on high speed beat the softened butter and sugar until light and fluffy, about 3 minutes. Turn mixer to low speed and add the eggs one at a time, blending after each. Mix in the ricotta, then the Lemon Emulsion and juice. With mixer still on low, gradually stir in the flour mixture until just combined. Do not over-mix. The dough will be very soft.

Using a large, round ice cream scoop, scoop 18 balls of dough onto the prepared baking sheet. Freeze dough balls uncovered for at least 8 hours or overnight. Dough should be very cold and stiff. (At this point, the dough balls can be placed in a zip-top bag and frozen for up to 2 weeks.)

Preheat oven to 325°F. and position racks in top third and center of oven. Remove dough from freezer and place 9 balls each on two parchment-lined cookie sheets spacing at least 2 inches apart. (If dough is very hard and brittle, allow to stand at room temperature for several minutes to soften slightly, however dough needs to be very cold when baked for cookies to keep their shape.) Bake cookies until lightly browned on the edges, about 18 - 22 minutes, rotating the pans from top to bottom and front to back halfway through baking time.

Remove from oven and cool cookies on the pan for 5 minutes, then transfer to a rack and cool completely before icing.

To make lemon icing, in a large bowl beat the butter and confectioners' sugar at medium speed until well blended. Add the Lemon Emulsion and water and mix until very smooth.

Ice cooled cookies using about 1 tablespoon of icing per cookie. Top with grated lemon zest if desired.