Bring 2-3" of frying oil, such as tallow or olive oil, in a skillet over medium high heat to 350F, until shimmering.
Combine all the dry ingredients together in a large bowl. Mix well.
Working one chicken tender at a time, toss in the dry mixture, then back into the buttermilk mixture, then back into the dry mixture to double batter. Gently press the flour mixture into the chicken so it looks shaggy.
Fry in small batches for 3-4 minutes on each side, until golden.
Remove the fried chicken tenders with kitchen tongs to a paper towel lined plate.
Once all chicken is fried, work in small batches to fry a second time for 1-2 minutes, until deeply golden. Remove and place on a freshly-lined paper towel plate or wire rack to drain excess liquids.