Preheat the oven to 200°F. Line a sheet pan with a nonstick silicone mat and place it in the oven to warm.
In a large heavy-bottomed pot fitted with a candy thermometer, combine the sugar, butter, corn syrup, and milk. Heat over medium high until the mixture reaches 300°F, whisking frequently and brushing the sides of the pot with a pastry brush lightly dipped in water if you notice sugar stuck to the sides. This helps to prevent the mixture from crystallizing.
Once the mixture registers 300°F, turn off heat. Add the vanilla bean paste and baking soda, and stir vigorously, the mixture will bubble.
Stir in the desired amount of nuts and mix well.
Working quickly, pour the mixture onto the silicone mat on the warmed sheet pan and gently spread with a greased rubber spatula into a thin and even layer.
Sprinkle with the Maldon salt and let it sit until completely cool, about 30 minutes. Break the brittle into pieces. |