These tangy lemon-flavored jumbo cupcakes are baked in a popover pan. You can easily substitute a jumbo muffin tin if you prefer.
1. Heat oven to 350 degrees . Coat a popover pan (see Note) with nonstick cooking spray. Line each indentation with a paper liner, or line 6 indentations of a jumbo muffin tin with paper liners.
2. In large bowl, whisk flour, sugar, baking powder and salt.
3. In small bowl, whisk milk, lemon zest, juice, egg, egg yolk and oil. Make a well in the flour mixture; add milk mixture. Stir until all flour mixture is moistened. Stir in poppyseeds.
4. Transfer batter to prepared pan, a heaping 1/3 cup per indentation. Bake cakes at 350 degrees for 25 minutes.
5. Remove cakes immediately from pan; cool completely on a wire rack.Icing:
6. In small saucepan (not nonstick), mix sugar, egg white, lemon juice, 2 tablespoons water, corn syrup, cream of tartar and salt. Heat over medium-low to medium heat, beating continuously with an electric mixer until medium-stiff white peaks are formed and an instant-read thermometer registers 150 degrees , about 7 minutes. Remove from heat. Beat an additional 1 minute.
7. Spread cooled cupcakes generously with icing, about 3 tablespoons per cupcake (there will be icing left over). Slip cakes into clean cupcake liners, if desired, and tie with ribbon or string.