Here is the full list of all 20 Cake Bash achievements.
Complete the playable tutorial!
Complete 5 matches of Get Tasty
Collect all of the Gummy toppings in the Collection Menu
Collect all of the Fancy toppings in the Collection Menu
Collect all of the Creature toppings in the Collection Menu
Fully complete the Toppings section of the Collection Menu
Buy a random topping when you have 3 coins or fewer at the final Get Tasty shop...
Obtain 3 or more combo toppings in a single game of Get Tasty
Play 3 Bashes at the Beach
Play 3 Bashes at the Birthday
Score 3 golden fruits in a single match of Fruity Pie
Win a match of Fondue or Die without getting anything bad
Achieve 5 perfect shots in a single match of Bakewell Ballet
Toast 3 or more perfect marshmallows in a single match of Campfire
Catch 3 masked pieces of cake in a single match of Caterpillar
Bash 8 or more wasps in a row in Wasp Attack
Stack 10 or more ice cream scoops in Neapolitan
Hit a hermit crab with a cocktail umbrella
Use only megabashes for the duration of a 4 player Bash, and win!
Completely fill your Collection Menu