Whipped Lemon Cream
In a large bowl, whisk together the dry ingredients: flour, baking powder and salt. Cream butter and sugar on medium speed until pale and fluffy, about 8 minutes.
Add eggs, one at a time, beating thoroughly between each addition, scraping down sides of bowl as needed. Beat in vanilla.
Reduce speed to low; add flour mixture in 2 batches, alternating with sour cream and beating until just incorporated.