Cheesecake Filling
1-In a medium bowl, mix together the: In a medium bowl, mix together the cream cheese, sugar and lemon zest.
2-Use a teaspoon to scoop a heaping: Use a teaspoon to scoop a heaping teaspoonful. Roll into a ball and place on a parchment-lined baking sheet. Repeat with remaining cream cheese until there are at least 18 balls.
3-Place cheesecake balls in the freezer until: Place cheesecake balls in the freezer until firm and frozen.

Cookies
4-In a medium bowl, whisk together flour,: In a medium bowl, whisk together flour, baking soda and salt. Set aside.
5-In a large bowl, add sugar and: In a large bowl, add sugar and lemon zest. Rub the sugar and zest between your fingers to increase the lemon flavor.
6-Add melted butter to the bowl and: Add melted butter to the bowl and use an electric mixer to mix until butter is absorbed. Add egg and egg yolk and mix until combined, then mix in the lemon juice and vanilla. Scrape down the sides of the bowl as necessary.
7-Add dry ingredients to the wet ingredients: Add dry ingredients to the wet ingredients and mix just until combined.
8-Cover the mixing bowl and refrigerate the: Cover the mixing bowl and refrigerate the dough for at least 30 minutes. When ready to bake the cookies, preheat the oven to 350 F. Line a baking sheet with parchment paper.
9-Remove the dough from the refrigerator and: Remove the dough from the refrigerator and use a medium cookie scoop to scoop 1 ½ Tablespoons of dough and roll into balls. Slightly flatten the ball, place a frozen cheesecake ball in the center and wrap it inside the dough. Roll dough back into a ball. Work quickly so the dough stays relatively cold before baking.
10-Roll each dough ball in granulated sugar: Roll each dough ball in granulated sugar and place on prepared cookie sheet about 3 inches apart.
11-Bake cookies for 10-12 minutes or until: Bake cookies for 10-12 minutes or until the edges are set and the centers are soft. Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.