I used this recipe at least 4 times this month. The first time, I was too sleepy in the midnight( ususally it's my baking fun time), I doubled all the ingredients but miseed one stick of the butter. But muffins turned out very fine. I served them for 20 parents in my son's graduation party. The second time I used vegetable oil insteaded of the butter. It's a little dry and not rich enough. The third time I tried the whole wheat flour instead of the regular flour, turns out perfect! The fouth time I used the almond flour instead of the regular flour. It's a totally tragedy. The muffins had to eaten in the cake pan. I smashed one muffin to my 3 years old boy as his snack this morning. He was okay with that anyway. I guess this recipe will be my year around breakfast recipe. Thank you, Tammy!