1-First Step: Mise en place Preheat oven to 425°F (220°C) when you are ready to bake. Line a muffin tin with 11 paper liners. Measure all ingredients precisely, preferably by weight for the flour (2 1/2 cups equals 320g). Bring eggs, milk, and sour cream to room temperature for even mixing. Zest two lemons and squeeze the small amount of lemon juice called for in the batter.

2-Second Step: Dry ingredients In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, salt, and poppy seeds. Whisking distributes the poppy seeds and activates the baking powder to sit evenly across the flour.

3-Third Step: Wet ingredients In a separate bowl, combine the melted unsalted butter with vegetable oil. Add the eggs and whisk until smooth. Stir in the sour cream, vanilla extract, lemon zest, lemon juice, and milk. Mixing the wet components until smooth makes folding easier and prevents overworking the gluten in the next step.

4-Fourth Step: Combine batter and rest Pour the wet mixture into the dry ingredients and gently fold with a rubber spatula until just combined. Aim for a few streaks of flour remaining but no large pockets of dry flour. Cover the bowl tightly with plastic wrap and rest the batter at room temperature for 1 hour. Resting helps the baking powder fully activate and allows the flour to hydrate for taller, lighter muffins.

5-Fifth Step: Make the lemon simple syrup while the batter rests In a small saucepan over medium heat, combine 1/4 cup fresh lemon juice and 1/4 cup granulated sugar. Heat until the sugar dissolves and the mixture comes to a gentle boil, then reduce to a simmer for about 5 minutes. Place lemon peel from 1 lemon in a heat-safe bowl, pour the hot syrup over it, and let it cool at room temperature while the batter rests. The peel will infuse the syrup with extra citrus oil.

6-Sixth Step: Portion the batter After the hour rest, preheat the oven to 425°F (220°C) if it has cooled. Use a 1/4-cup measure or a large ice cream scoop to portion batter into liners. Fill each liner to the top, which gives tall domes as the batter expands. For best rise, use 11 liners as specified so each cup is full without overcrowding the pan. Use every other cup in a 12-cup tin for improved air circulation if you prefer even taller tops.

7-Seventh Step: Bake in two stages Bake at 425°F (220°C) for 8 minutes. This high initial heat jump-starts oven spring for a domed top. After 8 minutes, reduce the oven temperature to 350°F (175°C) and continue baking for an additional 8 to 10 minutes. Check doneness with a toothpick inserted into the center; it should come out clean with a few moist crumbs attached.

8-Eighth Step: Syrup and cool As soon as the muffins come out of the oven, brush the tops generously with the lemon simple syrup you made earlier. To help the syrup penetrate deeper, poke each muffin a few times with a toothpick before brushing. Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool for 15 minutes. Optionally sprinkle extra poppy seeds on top while syrup is still tacky for a pretty finish.

9-Final Step: Serve and store Serve warm for best flavor and texture. The syrup keeps them moist and glossy. These muffins are great with coffee, tea, or a dollop of yogurt. For make-ahead, see storage section below for refrigeration and freezing tips.