Line an 8x8 inch square baking pan with baking paper.
Combine the sweetened condensed milk, sugar, glucose or corn syrup, butter, white chocolate and vanilla in a heavy based saucepan. Stir, over low heat, without boiling, until the sugar is dissolved and the mixture is smooth.
Continue to stir for another 6-8 minutes over low heat until the mixture has thickened a little.
Add the sifted flour and stir through until well combined, then continue to cook over the low heat for another 3 minutes. It should become quite thick.
Remove from heat and allow to cool for a few minutes, before adding 1 cup of choc chips. Stir through only once or twice so they don’t melt, then quickly pour the fudge into your lined tin.
Sprinkle the last ¼ cup of choc chips over the top followed by the salt. Press down lightly with a spoon just so the salt is stuck in the fudge a little bit and won't just fall off when the fudge sets.
Leave for 30 minutes to cool at room temperature, then cover with plastic wrap and refrigerate 3-4 hours or overnight.
Cut into squares and serve.
For best results you should always weigh ingredients like flour and sugar. Kitchen scales are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).