Preheat the oven to 320-325°F and line a muffin pan with 12 cupcake liners.

In a large mixing bowl, combine the eggs, vegetable oil, buttermilk, whole milk, and vanilla extract. Beat well to combine.

Mix in the granulated sugar and salt until well incorporated.

Sift in the flour and baking powder, stirring until just combined.

Fold in the lemon juice and lemon zest by hand.

Divide the batter into the cupcake liners and bake for 20-22 minutes until golden and springy.

In a heatproof bowl over simmering water, combine lemon zest, lemon juice, egg yolks, sugar, and butter. Stir for 10-15 minutes until thickened, then let cool.

Once cooled, core the middle of each cupcake and fill with lemon curd.

In a clean bowl, whip the egg whites and cream of tartar until stiff peaks form. Gradually add sugar, whisking until smooth.

Pipe the meringue onto each cupcake and toast using a blowtorch or broiler until lightly browned.