Preheat the oven to 350°. Line 2 cookies sheets with Silpats or parchment paper.

In a mixing bowl, whisk together flour, baking powder, baking soda, and salt. Set aside

In a large mixing bowl, beat butter and sugar until smooth and creamy, about 3 minutes. Add eggs, vanilla, lemon emulsion (if using), and lemon zest. Mix until well blended.

With the mixer on low speed, add one-third of the flour mixture to the butter mixture. Add half the sour cream. Add another third of the flour mixture. Add remaining sour cream and remaining flour mixture and mix until blended.

Use a cookie scoop (I use a 1 tablespoon scoop - put the recipe suggestions a 2 teaspoon scoop) to drop the dough about 2 inches apart on the prepared cookie sheets. Top with sprinkles.

Bake until the edged of the cookies are lightly browned about 11 - 13 minutes. Cool on the cookie sheets for 3 minutes. Transfer to wire racks to cool completely.

Store in an airtight container for up to 3 days, or freeze for up to 3 months.