Warm milk in a cast-iron dutch oven or a large pot.
Add sugar, brown sugar, and a pinch of salt.
YOU NEED A CANY THERMOMETER THAT IS ACCURATE
Cook until it reaches 235 to 240 degrees "soft-ball stage". A good way to text “soft-ball” stage without a thermometer is to drop a small amount, a couple of drops of the candy, into cold water it will form a softball.
Stir almost constantly to prevent sticking and burning. If the candy burns, you have to start over. If you are using a thermometer attached to the side of the pot, make sure that it does not sit on the bottom of the pot. You will not get a correct reading.
Once the candy reaches 235 to 240 degrees, remove from the heat.
Next, add the butter and pecans.
Next, stir the candy about 100 strokes to incorporate the pecans.
Spoon the candy about 1 to 2 TB size onto a sheet of wax paper or parchment paper.
Spoon quickly before the candy starts to harden.
Allow them to cool and dry.
Then, carefully turn them over to dry the other side.
Store them in an airtight container or wrap each one in plastic wrap. You can layer them in a plastic container with parchment paper or wax paper between them and freeze them.
Pralines will cool and harden in 10 to 15 minutes.
They will last for months in the freezer.