Line two cookie sheets with parchment paper.

Toast pecan halves in a 350°F oven for 6–8 minutes or in a dry skillet over medium heat for 3–4 minutes. Watch carefully so they don’t burn. Let cool.

In a medium saucepan, melt the butter over low heat, stirring until fully liquid.

Add granulated sugar, packed brown sugar, salt, and heavy cream to the pan. Whisk until combined.

Cover the saucepan and raise heat to medium so the mixture comes to a boil. Keep it covered and boil for about 2–3 minutes to reduce crystallization risk.

Remove the lid, clip a candy thermometer to the pan, and cook uncovered until the mixture reaches 242°F (soft-ball stage), about 5 more minutes. Stir occasionally.

Remove the pan from heat. Quickly stir in the toasted pecans and vanilla, whisking until the glossy mixture turns creamy. This step is fast — don’t delay.

Using two spoons or a small ice cream scoop, quickly drop mounds onto the prepared sheets. Space them so they don’t touch.

Let pralines cool and set for 30–45 minutes at room temperature. They’ll firm up but stay tender in the center.