I have a number of my great-grandmother's recipes for aebleskivers -- different occasions call for different types of spherical pancakes, am I right? -- some stuffed, others fancied up with spices. This is the most basic, and the one I turn to most often.
In a large bowl, beat the eggs well to combine, and then add in the sour milk and oil and mix well with a whisk (or hand mixer).
Add all of the dry ingredients to a separate bowl and whisk to combine.
Add the dry ingredients into the bowl with the wet ingredients, and whisk until everything is combined (or use a hand mixer).
Depending on your stovetop and your aebleskiver pan, you'll want the heat between medium and medium-low. I generally start at medium and lower down to medium-low as I work my way through the batch. Oil the wells of your pan (or don't, if you have a non-stick pan) and fill each well about 2/3 full with batter.
Cook until the edges set and you start to see some bubbles in the middle (like pancakes), and then flip them over (I like to use a chopstick) -- you'll be looking at a cooked dome. Cook until the aebleskiver is fully set -- if you aren't sure, pinch one open and check.
Remove cooked aebleskivers from pan and start another batch! Cooked aebleskivers can hang out in a bowl, or in an oven on low heat (I put them on a cooling rack set on a baking sheet in the oven).
Serve with whatever accoutrements you enjoy with pancakes. Growing up I never had them with syrup -- I used to treat each one like a mini Pac-Man: pop open its mouth, stuff it full with butter and jam, and eat it with my fingers. Now I'm okay with the transgression, and even endorse the syrupy, peanut butter, and banana mess pictured above.