Add the butter to the dry ingredients and using your hands rub the butter into the mix until it is completely combined, with no visible pieces of butter remaining (or add in the oil). Add the beaten egg to the dough and mix together until completely combined.
Place the ball of dough in the center of the lined flat baking sheet and cover with a second piece of parchment paper. Using a rolling pin, roll out the dough into a rectangle that’s approximatly ⅛” - 1/16” inch thick.
Using a pizza cutter, cut the dough into squares. If you end up with leftover scraps of dough, gather them up and repeat the rolling process.
Sprinkle the dough with flaky sea salt or remaining 2 teaspoons seasoning, pressing down lightly to make sure the seasoning sticks.
Bake for 15-20 minutes, until golden brown and crispy.
Store crackers in an airtight bag or container for up to 3 days.