Bake That Cake
From Halopedia, the Halo wiki
Bake That Cake is an achievement in Halo: The Master Chief Collection. It is awarded by beating the 30,000 point par score on Tip of the Spear in Halo: Reach. Though it can theoretically be unlocked on any difficulty, more points are awarded in campaign scoring when playing on higher difficulties.
The name of the achievement references the cut dialogue of Jun-A266 in the opening cutscene of the campaign level: "Time to bake that cake we made last night!"