As an auntie to triplets, I know finding the right dessert can sometimes be very tricky since kids can have really different likes and dislikes. But this loaf cake pleases just about everyone, young and old alike, and I use assorted Pop-Tarts flavors in it so my niece and nephews will all find a flavor that they like.
For the cake: Preheat the oven to 350 degrees F. Generously spray a 9-by-5-inch loaf pan with nonstick baking spray. Line the pan with parchment paper and spray the paper. Set aside.
Trim off the unglazed ends of the Pop-Tarts (this will make sure the tarts fit in the pan without touching the sides). Set aside.
Combine the butter, granulated sugar and lemon zest in the bowl of a stand mixer fitted with the paddle attachment and beat until light and fluffy, 2 to 3 minutes.
Whisk the eggs together in a medium bowl. Beat them into the butter mixture in 2 additions, scraping down the sides of the bowl between additions and beating until incorporated.
Sift the flour, cornstarch, baking powder and salt into a medium bowl. Set aside. Combine the milk and vanilla extract in a liquid measuring cup.
With the mixer running, add a third of the flour mixture to the bowl. Add half of the milk mixture. Continue alternating the flour and milk mixtures, ending with flour. Stop and scrape the bowl and paddle, then mix for 20 seconds longer.
Beat in the sour cream until incorporated. Stop and scrape the bowl. Beat for an additional 10 seconds.
Spread 1 cup of the batter evenly over the bottom of the prepared pan. Top with 2 Pop-Tarts making sure the tarts don’t touch the sides of the pan. Spread 3/4 cup of batter over the tarts. Top with 2 more tarts, then spread with another 3/4 cup batter. Top with the remaining 2 tarts and spread evenly with the remaining batter. Bake until the top is golden brown, 50 to 55 minutes.
Allow the loaf to cool completely in the pan before unmolding. Once cool, place upside down on a glazing rack or wire rack.
For the glaze: Combine the confectioners’ sugar, milk, vanilla and melted butter in a medium bowl and whisk until very smooth. If more milk is needed to form a pourable glaze add it a teaspoon at a time. Pour the glaze over the top of the cake, letting it run down the sides. Top with sprinkles and let the glaze set before slicing and serving.