1 c fresh lemon juice, about 6 lemons (no bottled, please) .
1 3/4 c sugar .
1 1/2 c granulated sugar .
1 tsp unflavored gelatin, plain .
12 tbsps unsalted butter, softened, but still cool .
lemon curd filling .
1 c whole milk, room temperature .
6 large egg yolks, from large eggs (reserve egg whites for cake) .
1/8 tsp salt .
8 tbsps unsalted butter, cut into 1/2 inch cubes & frozen .
2 large egg whites, from large eggs .
1 tsp salt .
1 tbsp fresh lemon juice (again, no bottled)
Directions
Step #1 Filling: Measure 1 tbsp lemon juice into a small bowl; sprinkle gelatin over the top.
Step #2 Heat remaining lemon juice, stirring every once in awhile until sugar dissolves & mixture is hot, & salt in medium non-reactive sauce pan over medium high heat, sugar, but not boiling.
Step #3 Whisk eggs & yolks In a large-ish non-reactive bowl.
Step #4 Whisking constantly, slowly pour hot lemon-sugar mixture into eggs, then return mixture to saucepan.
Step #5 Cook over medium-low heat, stirring constantly until mixture reaches 170° & is thick enought to leave a trail when a spatula is scraped along the bottom of the pan, about 4-6 mins.
Step #6 Immediately remove pan from heat & stir in the gelatin mixture until dissolved.
Step #7 Stir in frozen butter until incorporated.
Step #8 Pour filling through a fine-meshed strainer into a bowl.
Step #9 Cover up surface with plastic wrap; put in the fridge until firm enough to spread, about 4 hrs.
Step #10 Cake: Preheat oven to 350°.
Step #11 Grease & flour two 9-inch cake pans & line with parchment paper.
Step #12 In a medium bowl, whisk together egg milk, egg whites & vanilla.
Step #13 In a mixer bowl, mix flour, sugar, baking powder & salt; mix at slowish speed.
Step #14 Add butter one piece at a time, continue to beat until mixture resembles moist crumbs & no visible butter chunks.
Step #15 Add all but 1 c of milk mixture to crumbs & beat at medium speed until mixture is pale & fluffy, about 1 1/2 mins.
Step #16 With mixer running, add in the remaining 1/2 c milk mixture, beat 1 mintute more.
Step #17 Divide batter evenly between cake pans.
Step #18 Bake 23-25 mins or until toothpick in center of cakes comes out clean.
Step #19 Loosen cakes from side of pan with a small knife, remove parchment paper, cool in pan 10 mins then remove this from pan onto greased wire rack, invert again & cool completely.
Step #20 Icing: Combine all ingredients in a mixer bowl or heatproof bowl.
Step #21 Set over medium saucepan filled with 1-inch of simmering water.