Set the butter out to soften.
Adjust the oven rack to the lower-middle position. Preheat the oven to 375 degrees. Spray a 12-cup muffin tin or line with paper liners.
Mix the flour, baking powder, baking soda, salt, poppy seeds and lemon zest. Set aside.
Beat the butter and sugar with an electric mixer until light and fluffy. Beat in the eggs. Alternate adding the flour and yogurt about 1/3 at a time. Beat just until combined.
Spoon half the batter into each muffin cup. Use a spoon to make a well in each cup of batter, dipping it into water if necessary to keep the batter from sticking. Drop a teaspoon of lemon curd in each well. Top with the remaining batter.
Bake at 375 degrees for 25 minutes or until golden brown. Set the pan on a wire rack to cool slightly, then remove the muffins from the pan.