Preparation: Lemon filling. In small saucepan over low heat, whisk egg yolks, sugar, flour and salt. Whisk in lemon juice, lemon zest, water and melted butter. Increase heat to medium and, whisking constantly, cook until lemon filling is smooth and thick, about 7 min. Remove from heat and set aside

Preheat oven to 375

Make cupcakes: in medium bowl, beat butter and sugar until light and fluffy. Beat in eggs, lemon juice, baking powder, and salt. Beat in flour until just combined

Divide cupcake batter between 12 cupcake liners in muffin pan, bake 15-16 minutes until center of cupcake firms up. Remove cupcakes from oven and cool 5 to 8 minutes. DO NOT TURN OVEN OFF

Make meringue: beat egg whites and salt until mixture begins to stiffen, add sugat and beat meringue until stiff and peaks

With knife, remove center of cupcake, leaving layer of cupcake beneath. Discard core and fill cupcake center with lemon filling

Scoop dollops of meringue evenly, spreading out to edges and tapping spoon on top to make peak. Return to oven and bake 5-6 minutes or until peaks are golden brown remove and let cool for 10 minutes refridgerate for hour or more before serving.