Magdalenas are small sweet cakes that are rich-tasting, but light and fluffy. The Spanish traditionally eat them at breakfast with café con leche, and they are said to have originated in Aragón. They are also good with hot chocolate.
Preheat the oven to 375 degrees Fahrenheit (200 degrees Centigrade). Measure 1/4 cup sugar into small bowl and set aside.
Beat the eggs with 3/4 cup sugar until the mixture is light.
In a small sauce pan, melt the butter on medium on the stove top. Or, melt it in the microwave. Make sure that the butter cools slightly and is not bubbling. As you continue to beat the egg mixture, slowly pour in the melted butter, making sure to mix thoroughly. Stir in the lemon zest, vanilla, and milk.
Measure out the flour into a separate bowl. Add the baking powder to the flour and mix thoroughly.
While stirring the egg mixture, add in the flour mixture. Continue to stir until all ingredients are mixed well. The batter will be very thick.
Place paper liners in to cupcake pan. Use a large serving spoon to spoon batter into pan, filling each one half full. Batter will more than double in size when baked. Use a teaspoon to sprinkle each magdalena with a bit of the reserved sugar.
Place pans on the middle shelf of the preheated oven for 18-20 minutes, until magdalenas have turned a golden color. Remove from oven and allow to cool for 5 minutes before taking out of the pan to cool further.