Chewy, Gooey GFCFSF Brownies (Egg-free and Rice-free, too!)

Since becoming rice-free I haven't been able to use the prepared brownie mixes (like Namaste). This recipe was posted by "danniah1" on the GFCFKids yahoo group, so I tried it. It's really great. My son doesn't like chocolate much, but my daughter likes these in her lunchbox, and I've been sneaking one every now and then for a yummy chocolate fix. My husband says these are "the best brownies [he's] ever had!" These are gluten-free, casein-free, soy-free, rice-free, egg-free, corn-free, and coconut-free.

Ingredients
1 cup + 2 TBSP garbanzo bean flour
1/2 cup + 1 TBSP potato starch
1/4 cup + 1 TBSP tapioca flour/starch
2 cups raw or unrefined sugar (use less if you'd like)
3/4 cup cocoa powder
1 teaspoon GF baking powder
1 teaspoon salt
1 cup water
1 cup oil (olive, canola, grapeseed, coconut would work)
1 teaspoon vanilla
3/4 cup GFCFSF chocolate chips

Directions
Preheat oven to 350 degrees F. In a large bowl, combine the flour, sugar, cocoa powder, baking powder, and salt. Pour in water, oil, and vanilla; mix well. Stir in chocolate chips and mix until evenly combined. Spread evenly into a greased 13 x 9 inch baking pan. Bake for 25 to 30 minutes. (They may need slightly more baking time if you like the brownies a little less gooey inside.)

Yield
I cut these into 24 small brownies (see photo). They are rich enough that one smallish brownie is sufficient. :)

Note
These do get gooey in the middle, but we like them that way. Let them cool a lot before slicing/removing them (if you can wait, we usually can't)! I then freeze the individual brownies in a glass storage container, stacked between wax paper. I eat them straight from the freezer; they are sufficiently gooey enough that they are not rock-hard when frozen. They're just nice and cold brownies. Delicious! Pop a frozen one into a small container and stick it in the kids' lunchboxes. These would work well for a bday party or to keep frozen at school as replacement foods for other kids' bday parties too.