In a large bowl, whisk together flour, cornstarch, salt, baking powder, and baking soda. Set aside.
In a large bowl using an electric mixer, cream together butter and sugar on medium speed, until light and fluffy. Add eggs, and vanilla and almond extracts; beat until well combined, scraping down sides of bowl as needed.
Add flour mixture to wet ingredients; mix until combined. Gently fold in sprinkles.
Bake 7-9 minutes or until edges are lightly browned. Cool Heart Funfetti Cookie Cake Bars in pan on wire rack for 8-10 minutes; transfer to wire rack to cool completely before frosting.
For Buttercream Frosting
In a large bowl using an electric mixer, cream butter until creamy and smooth. Add salt, and vanilla and almond extracts; mix until combined.
Turn mixer on lowest speed and slowly add powdered sugar; mix until creamy. Add a tablespoon of milk, adding an additional tablespoon of milk until desired consistency is achieved. For colored frosting, add a few drops of gel food coloring in the desired color; mix until combined.
Once Heart Funfetti Cookie Cake Bars have completely cooled, frost using a no.6 decorating tip or icing spatula. Immediately add sprinkles, heart quins, or your own festive flair. Eat & Enjoy!
Notes
Store Heart Funfetti Cookie Cake Bars in an airtight container in the fridge; will keep for 4+ days.Heart Funfetti Cookie Cake Bars are best served within 1-2 days at room temperature.