Try to break the meringue pieces at the top of the board before you destroy the cake, to allow the bombs to mix in with the candy early on: otherwise you’ll end up with a flood of 15 move time bombs when the board gets cleared up. It’s not impossible to deal with the bombs even if you end up getting flooded, but it is difficult to clear them up whilst trying to make the purple order.
Other than that, make colour bombs, and mix them with purple striped candy whenever possible. Make special candy with the other colours if the chance arises but don’t lose sight of your goal.
The order in level 374 is 150 purple candies in 50 moves. With a large board that has a cake bomb in the middle it would seem pretty easy but there are 4 bomb makers at the two end columns which make 15 move bombs and these are easily activated by removing single meringue swirls and so will distribute 36 bombs when the cake bomb is activated.
The key tip for this level is to make as many special candies s you can. It is so easy to be distracted by trying to remove all of the bombs and not think about the task in hand. Therefore try to ignore the numbers on the bombs, especially when they first appear and try to make special candies from them. Color bombs are great, especially combined with striped candies, purple candies or a colour candy of a bomb that is about to explode. If you cannot make a special candy then look at the bombs and try to eliminate ones with the lowest levels. Do not work on the purples as they will remove themselves as you play and only when they get down to under twenty, should you start looking for matches to help you to win.
A bomb cooler could be the most useful booster for level 374. However, special candies can be helpful too, although perhaps not so much as the bomb cooler.