Mix dry ingredients. Whisk together the flour, baking powder, baking soda, and salt in a large mixing bowl. Then, set aside.
Cream butter and sugar. In a separate large bowl, use an electric mixer on medium-high speed to beat the softened butter, sugar, and eggs until the mixture is light and fluffy, about 3-5 minutes.
Add wet ingredients. Add the sour cream, lemon zest, and lemon juice to the butter mixture. Blend on medium-low speed until fully combined.
Combine. Slowly add the flour mixture to the butter mixture, one cup at a time, mixing at low speed until combined. The dough will be very soft.
Chill the dough. Cover the bowl with plastic wrap and refrigerate the dough for 1 hour to firm up. Towards the end of the chilling time, preheat the oven.
Prep. Preheat the oven to 375°F (190°C). Then, line baking sheets with parchment paper or lightly coat with cooking spray.
Bake. Using a tablespoon, scoop rounded portions of dough and drop them onto the prepared baking sheets, spacing each cookie about 2 inches apart. Bake the cookies for 10-12 minutes until the edges and bottoms are lightly golden. If baking multiple sheets at once, rotate them halfway through for even baking.
Cool completely. Remove the cookies from the oven and let them cool on the baking sheet for 2-3 minutes before transferring them to a wire rack to cool completely.