Make the saffron lemon curd: In a medium-sized saucepan, whisk the eggs and butter together until fully smooth and blended, with no streaks. Add the lemon juice, butter and saffron, and bring the pot to a low simmer over medium-low heat, whisking while the butter melts. Continue to whisk while the mixture slowly cooks and thickens to a pudding-like consistency, about 10 minutes. Pour through a fine-meshed sieve, then set the finished curd aside.
Make the Dutch baby: Preheat the oven to 425 F. Blend the flour, milk, sugar, eggs and salt until fully combined. Melt the butter in a skillet over medium heat, then pour in the batter. Let it cook undisturbed for 1 minute, then move the pan to the oven. Bake until golden and puffy, about 10-13 minutes. Serve with a sprinkle of powdered sugar and the lemon curd.
