Vanilla muffins/cupcakes

It has been a long break since I have been baking. School
re opens, busy with fitting into new routine.

Sunday 11pm, I suddently realise there isn't anything
for the kids to bring to school for snacks the next day. I started
to prepare muffin for the kids. This recipe is tested on them since
they had been eating more then the usual at a playgroup
gathering. This time, I sprinkle on chocolate rice, chocolate chips
since I  did not prepare any frosting. The kids still love it.

As it is so late, i did everything by hand, creaming the butter and
sugar, then I add the eggs (the recipe actually says mix all 
together). The mixture becomes like mashed tau huey. Is it
suppose to be like that ? I did not manage to get the mixture to
be smooth as it is pretty late, so i just dump in the flour, mix and
pour into paper cases. It will be edible anyway, probably just not
nice looking. So there you see, the top picture. My kids' school's
snack.

Since the previous muffin is so well received (even my hubby say
it is nice), I went ahead to try another similar recipe. Both uses
the same ingredients but in different proportion. This time, my
kids like it as much, but hubby said that the previous recipe's
taste better.

This time i use the mixer, as it involves 250g flour (previously
only ard 175g). The order of ingredient is still the same, cream
butter and sugar, add eggs, add flour, but this time, no curds.
I used chocolate rice and chocolate chips as well as the colourful
star and moon shape sugar sprinkles. ( I only want to test if the
sugar sprinkle melts, and they don't).

Very happy that I can bake snacks for the kids to bring to school.
I also realise that it is very convenient to bake muffins since I
just put the batter into cups, not much washing required after that.
A shorter cooling time. No need to cut the big cake too.

Should I start baking all the other cakes using paper cups ?
Here's the 2nd attempt with a similar recipe.