Preheat oven to 375℉.
Weigh and then freeze butter for at least 20 minutes, while gathering all other ingredients and equipment.
Mix together the dry ingredients in a large bowl (or on cutting board if doing that way)
Grate the frozen butter with a box grater on largest hole grater (or chop in very small pieces). *IF butter warms, place back in freezer for a few minutes to chill!
Cut butter into dry ingredients with the bench scraper.
Make a well in dry ingredients. Add buttermilk and mix lightly until just comes together as dough. Very important - Do not overwork.
Turn onto floured board or surface. Knead until soft, but not too wet. Use book method to fold dough into layers. Do this twice.
Roll out to 1/2” thick - no thinner! Use floured cutter to cut 2-inch biscuits (do not twist - ! - or the sides will not rise properly). Decide whether to put biscuits touching each other closely for softer sides or more spread apart for more crispy sides on half sheet pan.
Bake at 375˚ for 10 minutes and then turn the pan around to bake for another 10 minutes. (Convection ovens will bake more quickly - try 5 minutes and 5 minutes).
Melt butter, salt and agave in small pot or microwave.
Remove biscuits from oven when they look lightly browned on top and cooked all the way through.
Once biscuits are lightly browned and fully cooked, use the pastry brush to coat the tops with the agave butter.