I have a very basic vanilla cake recipe that use to work for me all the time and I loved it. But for some reason I think it may have gotten tweaked from me rewriting it and saving it in various places in my excel recipe spreadsheet.  I tried to lighten up a recipe the recipe by using the reverse creaming method with it. And I did half cake flour half ap flour.  The batter tasted wonderful, was pretty thick.  But when I baked it it domed perfectly at first, then spread up over the top of the edges a little.  I scooped the batter with my cupcake (ice cream) scoop 2/3 of the way as always.  I ended up having to trim the edges to get even sides after I removed them from the pan. And the end result is a very moist fluffy cupcake, a little dark on the bottom but the top separates away from the rest of the cake and is a little crusty.  Help!

Here's the recipe. I added a few tablespoons of instant coffee granules (per another recipe) the last 30 seconds of reverse creaming method to make a coffee speckled vanilla cupcake. 

2 cups sugar

3 cups flour

4 eggs 1 tbspn vanilla 1 tbspn bk pwdr 1 cup milk 1 cup butter

You're missing salt, about a teaspoon. 

however the recipe looks ok, and reverse creaming normally does work fine with a mix like this.

Yes the batter is thicker.  It may be better cooked low & slow.   I prefer to use this recipe with cakes, not cupcakes.