Add flour, baking powder and salt to a medium bowl. Whisk to combine.
Add 1/2 of the milk (I just eyeball it), the oil and bacon fat to a small pan. Stir to combine. Heat over low heat just until the the bacon grease has melted and small bubbles begin to form around the edge of the pan. Do not boil.
Simultaneously add the warm milk mixture and the remaining cold milk into the dry ingredients. Stir until most of the dry ingredients have been incorporated.
Dump dough onto a clean work surface (it will be dry and crumbly). Knead by hand for approximately 4-minutes. At the end of 4-minutes you should have a smooth round ball.
Wrap the ball of dough in plastic wrap and let it rest on the counter for 1 hour.
Divide the dough into 16 equal pieces. Form each piece into a smooth, round ball. Cover with plastic wrap and set aside.
Heat a cast iron skillet or comal over medium to medium high heat for 5 minutes. Meanwhile, lightly flour the work surface and rolling pin. Roll each disc into a 6″ round. To maintain round tortillas, roll in an upward motion once and then rotate the dough a quarter turn. Continue this pattern until the tortilla is round and the desired size.
Brush off excess flour and set aside until you have about 6 or 8 tortillas rolled out and ready to cook. Place a tortilla in the hot skillet. When it begins to form bubbles on top, flip the tortilla and cook on the other side. This should only take about a 1 minute in total to cook both sides. Stack cooked tortillas and cover with a kitchen towel until ready to eat.