Prepare Tangzhong by whisking together 1/4 cup of bread flour and 1/2 cup of whole milk over medium heat until thickened, about 2-3 minutes, then cool.

Activate yeast by combining 1/4 cup of warm milk with 1 tablespoon of sugar and sprinkling yeast on top. Let sit for 5-10 minutes until frothy.

Mix dough by combining the cooled tangzhong, activated yeast mixture, 1/4 cup of melted butter, 2 eggs, lemon zest, vanilla extract, and salt. Gradually add bread flour until a cohesive dough forms.

Knead dough on a floured surface for 8-10 minutes until smooth and elastic. Incorporate 2 tablespoons of softened butter as you knead, then let rise in a greased bowl for 1-2 hours until doubled in size.

Make lemon filling by mixing the zest of one lemon, 1/4 cup of sugar, and a pinch of salt in a bowl, rubbing zest into sugar.

Shape rolls by rolling out the dough into a large rectangle, spreading 4 tablespoons of softened butter, sprinkling lemon sugar mixture, and adding dollops of lemon curd before rolling tightly and slicing into 12 pieces.

Let the slices rise in a greased baking dish for 30-45 minutes until puffy before baking.

Preheat oven to 325°F and bake rolls for 20-25 minutes until lightly golden and a toothpick comes out clean.

Prepare frosting by beating 8 ounces of softened cream cheese and 4 tablespoons of softened butter until smooth, then mix in powdered sugar, lemon zest, and a pinch of salt.

Once cooled slightly, frost the rolls and serve warm, optional to swirl in extra lemon curd.