Preheat oven to 300 degrees F. Have ready two large baking sheets.
Mix the flour, baking powder, baking soda and salt; set aside.
In a mixing bowl, using an electric mixer, beat the coconut oil, brown sugar and vanilla until creamy.
Add the flour mixture to the vanilla mixture and stir until crumbly. Add the almond milk one tablespoon at a time, stirring until dough holds together. It will be on the dry side, but it should hold together and not fall apart when you press it down. I usually knead it just a bit to get it to come together (but don't overwork!).
Divide the dough in half.
Working one half at a time, press the dough down flat on a sheet of parchment paper, then using another sheet of parchment paper on top (or a sheet of plastic wrap if you prefer) roll to make a 6x12 inch rectangle about 1/8 inch thickness. Obviously you can't roll it right into a perfect rectangle, so start by rolling an elongated 1/8 inch slap and just tripping and re-piecing dough to make a neat rectangle.
With a pizza cutter, score rectangle cross wise to make 4 (3x6 inch) rectangles, then lengthwise to make 8 (3x6 inch) squares. If desired, make 4 more cross-wise slashes so that you have 16 small rectangles. Using a fork, make 4 or 5 pokes down each rectangle.
Do not separate the pieces. Put the parchment and scored dough on a baking sheet.
Repeat with second half of dough. You can put both the second triangle on the first baking pan or put it on a separate one and bake two sheets at a time.
Bake at 300 degrees F for about 20 minutes. Turn off the oven and allow the crackers to sit in the closed “off” oven for another 10 minutes.
Remove from the oven and let cool completely. If you want a softer cracker or if you rolled your dough thinner than 1/8 of an inch, skip the part where you let the crackers sit in the oven a while longer