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 minutes; remove from heat and set aside

Preheat oven to 375 degrees

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 a muffin pan; bake 15-16 minutes until center of cupcakes firms up; remove cupcakes from oven and cool 5-8 minutes (do not turn off oven)

Beat egg whites with salt until mixture begins to stiffen; add sugar and beat until meringue is stiff and forms pretty peaks (don’t overdo it)

With a sharp knife, remove center of each cupcake (about 1″ in diameter), leaving a layer of cupcake beneath cut out; discard cupcake core (or treat the weary baker to a tart little snack); fill cupcake centers with lemon filling

Divide dollops of meringue between cupcakes, spreading out to edges and gently tapping with back of spoon to form peaks; return cupcakes to oven and bake an additional 5-6 minutes until meringue peaks are golden brown; remove from oven and let cool 10 minutes; refrigerate an hour or more before serving – Makes: 12 absolutely delicious cupcakes