Set oven to 350°F (175°C)
Combine dry ingredients in a medium bowl and set aside
Cream together all wet ingredients in a stand mixer (or by hand with a whisk) until well combined
Add dry ingredients to wet and mix until batter is just combined (do not overmix)
Spread batter evenly among 12 muffin tins, filling each about ¾ full
Bake for 20–30 minutes, checking with a toothpick for readiness (this will depend on your oven—they should still be a pretty pale yellow on top)
Combine lemon juice, sugar, butter, eggs, and lemon zest in a 2-quart saucepan
Cook over medium-low heat, whisking constantly to prevent the eggs from curdling, until mixture thickens and bubbles rise to the surface, about 5–6 minutes
Remove saucepan from heat; transfer lemon curd into a large bowl. The curd will thicken more as it cools
Once cooled, cut small divots into the muffins, dust with powdered sugar, and add lemon curd to the center
