• Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners. Spray the cupcake liners with cooking spray to avoid sticking and to help with the removal of the liners.
• In a medium bowl, whisk together the flour, baking soda, baking powder, and salt until the flour mixture is well combined. Set aside.
• In a large bowl of a stand mixer, cream together the softened butter and granulated sugar on high speed until light and fluffy. Once done, lower to medium speed and beat in the eggs, one at a time, followed by the sour cream, lemon zest, vanilla extract, and lemon juice.
• Gradually add the dry ingredients to the electric mixer with the wet ingredients, alternating with the milk. Begin and end with the dry ingredients. Mix until just combined. Finally, stir in the poppyseeds until evenly distributed throughout the batter.
• Spoon the batter into the prepared cupcake liners, filling each about two-thirds full. Then bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
• Once the cupcakes are done, remove from the oven and let them cool in the pan for a few minutes. Then transfer them to a wire rack to cool completely. While the cupcakes are cooling, prepare the lemon frosting. In a mixing bowl, beat the softened butter until creamy.

How to Make Lemon Buttercream Icing

• In a mixing bowl, beat the softened butter until creamy and smooth.
• Gradually add the powdered sugar, about 1 cup at a time, beating well after each addition. Scrape down the sides of the bowl as needed.
• Add the lemon zest and lemon juice to the butter mixture. Mix well to incorporate the lemon flavor throughout.
• Place the icing in a piping bag with the icing tip of your choice. Pipe the icing over top of the cooled cupcakes. Top with poppyseeds and extra lemon zest.