Preheat oven to 325°F. Sift together flour, baking powder and salt into a bowl and set aside. Line 2 sheet pans with parchment paper. 

Cream the sugar and butter in a mixer fitted with the paddle attachment on high speed until light and fluffy, about 2 minutes. Reduce the speed to medium and crack in the eggs one at a time, beating well in between additions. Plop in the ricotta, vanilla and lemon zest and beat to combine. Add the flour mixture and beat on low until just combined, but do not overmix. Fold in the cherries (if using). 

Drop the dough in heaping tablespoons onto the sheet pans. Place in oven and bake, rotating pans halfway through the baking time, until the cookies are puffed, golden and cooked all the way through, about 20 to 22 minutes. Remove and cool on wire racks. 

When the cookies are completely cool, make the glaze. In a bowl, whisk together the confectioners' sugar and lemon juice to make a smooth glaze. Adjust the consistency with a little water or more confectioners' sugar to make a glaze thick enough to stick to the cookies when dipped. Dip the tops of the cookies in the glaze and let dry on racks.