Prepare the pan

• Line a baking dish with parchment paper and butter it lightly.
• Have the evaporated milk, butter and vanilla ready next to the stove.

Melt the sugars

• Combine the granulated sugar, brown sugar and corn syrup in a heavy saucepan.
• Cook over medium heat, stirring, until the sugar dissolves and the mixture comes to a boil.

Add the evaporated milk

• Slowly pour in the evaporated milk while stirring constantly so the mixture doesn't stop boiling.
• Attach a candy thermometer to the pan.

Cook the caramel to temperature

• Cook over medium heat, stirring frequently, until the caramel reaches 118 °C (soft ball stage).
• Keep an eye on the mixture so it doesn't scorch on the bottom.

Finish the caramel

• Remove the pan from the heat and stir in the butter, vanilla and salt until smooth.

Set the caramel

• Pour the caramel into the prepared dish and spread it evenly.
• Let it cool completely at room temperature until firm.

Cut and wrap

• Cut off one row at a time, then cut into individual squares.
• Sprinkle with flaky salt if you like and wrap each caramel individually in wax paper.