Beat the butter and sugar in a standing mixer until light and fluffy, about 3 minutes on medium high speed. Add the lemon zest and the eggs, one at a time, beating until incorporated. Stir in the lemon extract, if using.
Mix the flour, cornmeal, rosemary, baking powder and salt in a bowl until blended together.
Add the dry mixture to the butter on low speed in 2 parts, just until the dough comes together. Stir in the pine nuts. Cover the bowl and refrigerate for an hour or two, until the dough is firm and scoopable.
Heat the oven to 325 (160 C) degrees and line 2 large baking sheets with parchment paper.
Scoop the dough into tablespoon-sized balls (I like to use a cookie scoop) so they come out even) and arrange on the cookie sheets about 2-inches apart.
Bake 12 minutes, or until the cookies are puffed and slightly golden on the edges. Cool the cookies on the baking sheet 5 minutes before transferring to a rack to cool completely.
To make the glaze, stir together the powdered sugar, cream, lemon juice and zest until smooth. Spread some glaze on each cookie. Put a few rosemary leaves and a pine nut on the top.
The unglazed cookies can be frozen up to a month. Once glazed, keep them at room temperature 3 - 5 days.