Follow these simple steps to create your delightful Sprinkle Cake Roll:

1. Preheat the Oven: Preheat your oven to 375°F (190°C). Line a 15×10-inch jelly roll pan with parchment paper and lightly grease it.
2. Mix Dry Ingredients: In a medium bowl, combine the flour, baking powder, and salt. Set aside.
3. Beat Eggs and Sugar: In a large mixing bowl, beat the eggs and granulated sugar together until light and fluffy, about 5 minutes.
4. Add Vanilla and Milk: Stir in the vanilla extract and milk until well combined.
5. Combine Mixtures: Gradually add the dry ingredients to the egg mixture, gently folding until no lumps remain.
6. Fold in Sprinkles: Carefully fold in the rainbow sprinkles, ensuring even distribution throughout the batter.
7. Spread Batter: Pour the batter into the prepared jelly roll pan and spread it evenly.
8. Bake: Bake in the preheated oven for 12-15 minutes, or until the cake springs back when lightly touched.
9. Cool: Once baked, remove the cake from the oven and let it cool in the pan for 5 minutes. Then, carefully turn the cake out onto a clean kitchen towel dusted with powdered sugar. Peel off the parchment paper.
10. Roll the Cake: Starting from one short end, gently roll the cake and towel together. Allow it to cool completely in this rolled position for about 30 minutes.
11. Prepare Filling: While the cake cools, prepare the whipped cream cheese frosting if making homemade.
12. Unroll and Fill: Once the cake is cool, unroll it gently. Spread your whipped cream cheese frosting evenly over the cake.
13. Re-roll the Cake: Roll the cake back up without the towel, starting from the end where you first rolled it.
14. Chill and Decorate: Place the rolled cake on a platter. Chill in the refrigerator for at least 30 minutes. Before serving, decorate with extra sprinkles on top.