Preheat oven to 350 degrees. Sift flour and salt together. Coarsely chop 1 cup cashews; set aside. Process remaining 1 1/2 cups cashews in a food processor until finely chopped. Pour in oil. Process until mixture is creamy, about 2 minutes.

Put cashew mixture, butter, and sugars in the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed until fluffy, about 2 minutes. Mix in egg and vanilla. Reduce speed to low; gradually add flour mixture. Mix in reserved chopped cashews.

Shape dough into 1 1/2-inch balls; space 2 inches apart on 2 parchment-lined baking sheets. Bake 6 minutes; gently flatten with a spatula. Bake until bottoms are just golden, 6 to 7 minutes more. Let cool completely on sheets on wire racks.

Melt caramels with cream in a small saucepan over low heat, stirring. Let cool. Using a spoon, drizzle caramel over cookies; let set. Store airtight in single layers.

Whisk flour, cornstarch, spices, and salt in a bowl. Put butter and 1/3 cup sugar into the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale and fluffy. Mix in rum and vanilla.

Reduce speed to low, and gradually mix in flour mixture.

Divide dough in half. Place each on a piece of parchment paper; shape dough into logs. Fold parchment over dough; using a ruler, roll and press into a 1 1/4-inch log. Wrap in parchment. Chill in freezer 30 minutes (up to 1 month).

Preheat oven to 350 degrees. Unwrap logs. Cut into 1/4-inch-thick rounds; space 1 inch apart on parchment-lined baking sheets. Bake until just golden, about 15 minutes. Transfer cookies to wire racks; let cool 10 minutes. Gently toss warm cookies with remaining 2/3 cup sugar in a resealable plastic bag. Cookies can be refrigerated in airtight containers up to 2 weeks.