Combine butter, evaporated milk, sugar, and salt in a medium saucepan. Bring to a boil for 5 to 7 minutes, stirring constantly. Remove from heat.
Stir in the chocolate until melted and smooth. Fold in the almonds and marshmallows. Pour into an 8×8 baking pan, preferably silicone. Chill until firm, about 2 to 4 hours. Remove from pan and cut into squares.
