Preheat oven to 375°F (190°C).

In a large bowl, combine peanut butter, Crisco, light brown sugar, milk, and vanilla.

Beat with an electric mixer at medium speed until well blended.

Add egg and beat until just combined.

In a separate bowl, combine flour, salt, and baking soda.

Gradually add the dry ingredients to the wet ingredients at low speed.

Mix until just blended.

Drop by heaping teaspoonfuls 2 inches apart onto an ungreased baking sheet.

Flatten slightly in a crisscross pattern with the tines of a fork.

Bake at 375°F (190°C) for 7 to 8 minutes, or until set and just beginning to brown.

Cool on the baking sheet for 2 minutes.

Transfer cookies to sheets of foil to cool completely.