Line a cookie sheet with parchment paper and set aside.
Melt baker's chocolate in a microwave-safe bowl in the microwave at 30-second intervals. Stir after each interval until melted. You could also do this in a double boiler.
Add hot melted butter to the baker's chocolate.
Never add cold butter to melted chocolate, this may cause the chocolate to seize. [Tip: If the chocolate starts to seize you can add a bit more melted butter and reheat. This should help it to loosen back up.]
Your chocolate should be smooth and glossy.
I did not put how much stevia to add because different people have different tastes. What may be too sweet for one is not sweet enough to someone else. So add some stevia, taste, and add more if needed.
Pour chocolate mixture into a sandwich bag or piping bag. [Tip: if you put the bag into a mug and fold the top over the lip of the mug it makes it easier to fill.]
Push chocolate down to the bottom of the piping bag or to one of the corners of the sandwich bag.
Snip the corner of the sandwich bag if that is what you are using.
On a parchment-lined cookie sheet pipe out chocolate chips in rows.
To get a good looking chip, tap the bag (or piping tip) onto the cookie sheet and pull back up in a swoop motion.
Pipe all the chips until the chocolate is gone.
Place cookie sheet in the refrigerator or the freezer until chips are set. About 5-10 minutes.
You can now peel the chips off the parchment paper and use it as you would normally use chocolate chips.
If you are not using them right away, place them into a bowl with a lid or just into a sandwich bag.
They will be fine at room temperature, but just in case I like to store them in the freezer. They don't freeze together and I do not run the risk of them melting together.