i have a similar profile as you (2 years WE, science/eng background). when you write your essays, make sure to focus on why you would contribute to the school and to the classes despite your age. also talk about what specifically you want to do post-mba, even if you're not 100% sure. make sure it relates to the work you had been doing in school and in your job. if it doesn't relate, then think of a really good reason why you want to switch (although since youre so young, that may raise some red flags - IMO it would be better to just stay with the same path you've been on).
i've only done one app so far (HBS), but i used all of the above elements in my applications and was able to get an invite, despite my age (im 23 now, will be 24 next year @ matriculation). HBS is unique in the top 10 schools that they are definitely trending younger. i think you'd have a good shot there if you can make a convincing argument as to why you belong there.
looking at your top 10 list, i'd venture to say you haven't yet put in a lot of effort as to what specific schools/programs you want to apply for
. this is fine now, but for your essays , it's crucial that you have already done your homework about the specific schools and what programs they offer, so that you can write about SPECIFICS. just applying blindly to the top 10 programs in the country is a bad idea IMO. besides a waste of time/money in apps, you could have instead picked 3-4 schools that you know you like and concentrated your efforts on those.
finally, one big question that i've read was asked is "why get an MBA now?". it sounds like you don't have a really good reason for that (especially if you can get a promotion by staying an extra year). just something to think about. remember that your GMAT scores get saved for up to 5 years, so there's not necessarily a rush to get your app in this time around. good luck with whatever you choose