I like Pillsbury Gluten-Free Flour because it's the least expensive and has all the additives already in there ~ just measure like you would regular flour. If you're gluten-free for strict dietary reasons, you should use aluminum-free baking powder. But since I just prefer gluten-free as often as possible, since I feel better, I used regular baking powder here.
I like unsweetened plain almond, cashew or oatmilk ~ but you can use whatever type of milk you like.
I always use my grandmother's old pastry cutter (it may be older than I am, and that's OLD!), but you can use 2 forks to cut the butter into the flour. Don't pulse on your food processor b/c you'll over-mix the butter with the flour. Get an inexpensive pastry cutter at the grocery store (or an antique store ~ or on eBay)
Gluten-Free BAKING POWDER BISCUITS
2 cups gluten-free flour blend (one that has all the additives already included)
2 TB baking powder (mine was regular ~ you may want aluminum-free)
1 tsp. salt (any kind ~ I ground Pink Himalayan salt here, but sometimes use Kosher salt)
5 TB COLD butter, cut into cubes (mine was unsalted) ~ can use Oleo sticks for dairy-free
1 cup of milk (any type you want) ~ and a little extra to brush on top of the biscuits before you bake them.
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Preheat oven to 425. Line a baking sheet with parchment paper and set aside.
Put the dry ingredients in a big bowl and whisk together. Then add the COLD butter cubes ~ cut them into the flour with a pastry cutter (or 2 forks) until the butter is about pea-sized.
Add the milk and mix with a wooden spoon, just until it's mixed through (don't over-mix because you want the butter to stay in little chunks). I used a rubber scraper to get the little bits on the bottom of the bowl (and the sides) ~ and then smashed them in to form somewhat of a ball.
Turn the dough out onto a piece of parchment or waxed paper. Pat into whatever shape you need ~ about 1-1/2" thick. If you don't have a round cutter, then do a square or rectangle, and just cut squares with a knife! Put them onto the baking sheet and brush with a little milk.
Bake for 9-12 minutes, or until just starting to lightly turn golden ~ and the layers will begin to flake apart. The time will depend on how thick you made them (and your oven).
I got 10 round biscuits (using 2-1/2" cookie cutter), but it will depend how thick yours are or how big you cut them.