Preheat oven to 350°F. Line a 12 cup muffin tin with muffin liners.
In a mixing bowl, sift the flour, baking powder, baking soda, salt, and poppy seeds together. Set aside.
1 ¾ cup All-purpose flour, 1 teaspoon Baking powder, ½ teaspoon Baking soda, ½ teaspoon Salt, 1 ½ tablespoon Poppy seeds
Using a mixer, beat the butter, oil and sugar on high for 3 minutes. Add in lemon zest, lemon juice, and sour cream. Scrape the bowl.
7 tablespoon Unsalted butter, 1 tablespoon Oil, ¾ cup White granulated sugar, Zest of 1 lemon, ⅛ cup Lemon juice, ⅛ cup Sour cream
Add in the eggs one at time on low. Switch to high speed and beat for 2 minutes. The batter will appear separated, but that is from the lemon so this is normal.
2 Large eggs
Add in ⅓ of the dry ingredients and half of the buttermilk .Mix until just combined. Add in another ⅓ of the dry ingredients and the rest of the buttermilk. Mix. Add the rest of the dry ingredients.
½ cup Buttermilk
Use 1 ½ tablespoon cookie scoop to scoop the batter into the muffin tins. Fill them ⅔ full.
Bake for 16-18 minutes. The cupcakes are done baking when a toothpick inserted comes out clean. Let the cupcakes sit in the tin for 10 minutes before transferring to a cooling rack. Then allow them to cool completely.