>> Servings: 10

Sprinkle @sugar{1/2 cup} in a shallow heavy #3½-quart Dutch oven{}.

Cook over medium heat, stirring constantly, until @sugar{} melts (sugar will clump) and syrup is light golden brown. Note: This will take about ~{10 minutes}.

Remove from heat.

Combine remaining @sugar{2½ cups} and @all purpose flour{1 tablespoon} in a large #saucepan{}, stirring well.

Add @milk{1 cup} and bring to a boil - Stirring constantly. Note: This will take about ~{10 minutes}.

Gradually pour about one-fourth of hot mixture into caramelized sugar - stirring constantly.

Add remaining hot mixture (mixture will lump, but continue stirring until smooth).

Return mixture to heat.

Cover and cook over low heat ~{2 minutes}.

Uncover and cook, without stirring, over medium heat until a #candy thermometer{} reaches 238°. Note: This will take about ~{10 minutes}.

Add @butter{3/4 cup}, stirring to blend.

Remove from heat, and cool, without stirring, until temperature drops to 110°. Note: This will take about ~{1 hour}.

Add @vanilla extract{1 teaspoon}, and beat with a #wooden spoon{} or at medium speed of an #electric mixer{}, until of spreading consistency (about ~{20 minutes}).