Step 1

Line a rimmed baking sheet with wax paper. Gently melt the chocolate in a double boiler or in the microwave. Stir in the butter until the mixture is smooth and the butter has completely disappeared.

Step 2

Drop the pretzel bits into the chocolate and stir until all the pretzel pieces are coated. Then, using a fork, lift the pretzel bits out of the chocolate several at a time and push them onto the lined baking sheet, trying to make sure the individual pieces are separated from each other, for the most part. Transfer to the refrigerator to chill until the chocolate has hardened. Store in an airtight container until ready to use.

Step 3

Combine the cream, milk, 1/4 cup of sugar, corn syrup, and salt in a heavy-bottomed saucepan and heat to a bare simmer, then turn the heat down. Meanwhile, in a medium bowl, whisk together the egg yolks, malt powder, and the remaining 1/4 cup sugar.

Step 4

When the cream mixture is hot, whisk a ladleful of the hot cream into the egg yolks (whisk vigorously!) to temper them. Repeat with one or two more ladlefuls. Then, pour the egg mixture into the pot with the rest of the cream mixture.

Step 5

Cook the custard mixture over medium-low heat, stirring constantly, until it has thickened to a custard texture and coats the back of a spoon (it will be around 180 F). Pour the custard through a fine mesh strainer into a large metal bowl, then stir in the vanilla.

Step 6

You can chill your custard over an ice bath, but I have hated ice baths ever since organic chemistry (I don't like bain-maries much either for the same reason). I just stick mine, covered, into the fridge and leave it overnight or until it is completely chilled.

Step 7

Transfer your custard to your ice cream machine and process according to the manufacturer's instructions until it reaches the consistency of soft serve, adding the pretzel bits in the last minute or so of churning.

Step 8

Eat immediately (mmmm, soft serve), or transfer to an airtight container and chill for a couple hours until firm.