Preheat the oven to 350 °F (177 °C). Prepare a muffin pan with liners and spray with nonstick spray.
In a medium mixing bowl, whisk together the flour, baking powder, and baking soda.
In a stand mixer, cream the butter and sugar together. It should be light and creamy.
Beat the eggs in one at a time, until the mixture is smooth.
Mix in the vegetable oil, fresh lemon juice, milk and lemon zest.
Gradually mix in the dry ingredients (flour, baking powder, and baking soda mixture). Stir only until just combined, do not over mix.
Spoon the batter into the cupcake liners, filling just over half way.
Bake for 15 to 20 minutes, or until the top bounces back when pressed. Remove the cupcakes to a cooling rack.
When you are ready to assemble the cupcakes, prepare the meringue frosting. Using a hand or stand mixer, beat the egg whites and cream of tartar together until soft peaks form. Add the vanilla and continue to beat until you have stiff peaks. (about 5 minutes all together) Then slowly incorporate the sugar.
To assemble the cupcakes, use a cupcake scoop or spoon to remove a chunk from the middle of the cupcake. Spoon or pipe in some of the lemon curd. Then pipe on some of the meringue filling and toast it with a kitchen torch if you like.
Notes
You may want to make the curd the night before, as it does need time to chill.