Preheat oven to 300°F (150°C). Grease and flour a 10-inch tube pan.

Cream together butter, shortening, and salt until light and fluffy.

Gradually add sugar, creaming well until fully incorporated and smooth.

Beat in eggs one at a time, ensuring each is fully blended before adding the next.

Alternately add flour and evaporated milk, beginning and ending with flour. Mix until just combined.

Gently fold in butternut flavoring until evenly distributed.

Pour batter into the prepared tube pan.

Bake for 1 hour and 30 minutes, or until a wooden skewer inserted into the center comes out clean.

Let cool in the pan for 10-15 minutes before inverting onto a wire rack to cool completely.