Adjusting baking time and temp for small cupcakes?
The general rule of thumb with cakes and quick breads is that within certain limits:


The larger the cake the lower the temperature
The smaller the cake, the higher the temperature


The reason is that you want to get nice crust formation and browning in the time in takes the muffin or cupcake to cook through.  However, mini-muffins or cupcakes have so little mass that they will bake through quite quickly, and may be easy to over bake at higher temperatures.

This article at Baking Bites, in regards to converting standard cupcakes to mini-cupcakes recommends:


  While most cupcakes take about 15-20 minutes to bake, most mini
  cupcakes take from 9-14 minutes or so to reach donenss. Check your
  minis at 9 or 10 minutes with a toothpick and bake longer as needed.
  The only thing you really need to look out for is the fact that it is
  easy to overbake these miniature cakes, so keep a close eye on them
  while they’re baking and check them at very short intervals when
  they’re close to being done.


This matches my experience for full sized muffins and cupcakes:  full sized muffins should bake in about 18-22 minutes&mdash;if they take longer, raise the oven temperature on the next batch slightly.

They do not suggest changing the temperature for minis.  The tips at Cupcakes Take the Cake concur:


  If recipes don't specify mini baking times, note that minis will take
  more than half of the baking time recommended for standard size
  cupcakes.


My survey of a number of mini-cupcake recipes shows the general consensus is about 10 minutes, or half the time of a regular cupcake. 

Remember, however, the smaller the cake, the more little factors like your actual oven temperature, how much batter you put in the tin (and how consistently you fill each cup), the moisture level of your batter, and so on affect the outcome.

All of my experience is with standard sized cupcakes and muffins, or muffin tops.  If I had a mini, pan, I would determine the best baking time by:


Doing a half-tray, and checking it when they start to smell done (if you are an experienced baker, you will know what this means), or at about 8 minutes.
Continue checking every minute or so, until you find they are done with the toothpick test.
Bake a second half-tray to that time without all of the door opening, to confirm your findings.
Adjust as necessary, and you will then know the best time for your oven and that particular recipe&mdash;assuming you fill the tins consistently.  (I use a food disher&mdash;like an ice cream scoop&mdash;for this purpose.)


Note:  the purpose of the half tray is to have less cakes with a less than perfect bake.  Once you dial in the ideal baking time, go for full trays for less work.

I also suggest not doing multiple trays at the same time, as they will change the way the air circulates in the oven, and mask the radiant heat from each other.  This makes for less consistent results.