Heavenly cookies are a prestige item that gives a permanent 1% CpS (cookies per second) boost in the Beta 1.0501. Currently, they are glitched and give 10% each. You make heavenly cookies on the ascension screen where it says "Bake heavenly cookies". Each heavenly cookie costs 10 heavenly chips to bake. As the only other thing you can spend heavenly chips on are prestige upgrades, making these heavenly cookies are the heavenly chips' primary function. As you can imagine, heavenly cookies are replacing the heavenly chips' primary function in the live version.