Take butter and heavy cream out of fridge the same time.
Slice butter into ⅓ to ½ inch chunks, and scatter them in you mixing bowl.
Whip heavy cream till soft peak.
Let both rest at room temperature for at least 30 minutes to soften butter. I.E. Go bake your cake or start on some chocolate spiders.
After butter is soften (press a finger on it to check, butter should soft but still feel a little cold), now it's time to whip.
Whip butter on medium speed until all slices incorporated, turn off and scrape the bowl with spatula.
Turn to slowest speed setting, add all sugar into your butter, whip until sugar and butter are all mixed up.
Increase mixer's speed gradually (until almost highest speed) and whip until butter's volume is doubled/tripled while its color becomes pale.
Adjust speed down to medium, spoon in whipped heavy cream, one at a time, wait for the prior to fully mix before adding the next.
After finished adding whipped heavy cream, increase mixer speed to high for 15 second then reduce to lowest setting and beat for 3 minutes to smooth out the cream of air bubbles.
If cream becomes sweaty, let it rest for 15 minutes before beating again on high speed and smoothout with low. Note that it will be splatter (a lot) to beat on sweating butter, so cover the bowl well.
Divide, add color & extract to each portion and mix by hand with spatula to ensure all air bubbles are out.