In a double boiler, whisk together egg yolks, sugar, lemon zest, and fresh lemon juice for about 10 minutes until thickened. Remove from heat and whisk in cold butter until smooth.

Preheat your oven to 350°F (175°C) and line a muffin pan with paper liners.

In a mixing bowl, whisk together flour, baking powder, baking soda, and salt.

In a separate bowl, cream together butter until smooth, add sugar and mix until light and fluffy.

Add eggs one at a time, mixing well after each. Stir in Greek yogurt, vanilla extract, lemon zest, and lemon juice.

Fold the dry ingredients into the wet mixture until just combined.

Fill muffin cups halfway with batter, then add 1 tablespoon of lemon curd to each.

Top with remaining batter to cover the curd.

If desired, sprinkle with streusel topping.

Bake for about 25 minutes or until golden brown.

While cooling, whisk together powdered sugar and milk for glaze.

Drizzle glaze over cooled muffins and serve.