1. Whisk flour, baking powder, baking soda, and salt together in large bowl. Using hand-mixer, beat butter and sugar on medium speed until fluffy, 3-6 minutes. Add eggs, one at a time, and beat until incorporated, about 30 seconds. Reduce speed to low and beat in sour cream and lemon zest until combined. Add flour mixture and mix until incorporated, about 30 seconds. Refrigerated dough for 1 hour.
2. Adjust oven racks to upper-middle and lower-middle positions and heat oven to 375 degrees. Line 2 baking sheets with parchment paper.
3. Drop heaping 1-tablespoon mounds of dough onto sheets, spacing them about 2 inches apart. Bake until just golden around the edges, about 15 minutes, switching and rotating sheets halfway through baking. Let cookies cool completely on wire racks.
4. Whisk lemon juice and cream cheese together in bowl until combined (this takes some doing). Add powdered sugar and whisk until smooth. Spread 1 teaspoon glaze onto each cookie.
