Peanut butter-oatmeal sandwich cookies

Ingredients

• •1/2 cup brown sugar
• •1/4 cup granulated sugar
• •2/3 cup peanut butter
• •1/4 cup vegetable shortening
• •1/2 teaspoon salt
• •1 teaspoon baking soda
• •1 teaspoon vanilla extract
• •1 large egg
• •1 cup quick-cooking oats
• •2/3 cup flour
• •extra-fine salt (optional), for dusting on top
• •1 1/2 cup confectioners' sugar
• •1/2 cup peanut butter, heaping
• •5 tablespoon milk (or half & half)

Steps

1. 1Preheat the oven to 350°F. Lightly grease (or line with parchment) two baking sheets.
2. 2To make the cookies: Combine the sugars, peanut butter, shortening, salt, baking soda, and vanilla, beating until smooth.
3. 3Add the egg, beating to combine.
4. 4Stir in the oats and flour.
5. 5Drop the dough by the heaping teaspoonful onto the prepared baking sheets, leaving about 1 1/2" between them. A teaspoon cookie scoop works well here.
6. 6Using the flat bottom of a drinking glass dipped in sugar, flatten each cookie to about 1/4" thickness, about 1 1/2" diameter. If you're a fan of the popular sweet/salty flavor combo, sprinkle each cookie with the tiniest amount of extra-fine salt (or to taste; you know your own tolerance for saltiness).
7. 7Bake the cookies for about 12 to 14 minutes, until they're a medium golden brown.
8. 8Remove them from the oven, and transfer them to a rack to cool. Once they're cool, wrap airtight; they'll soften if left unwrapped.
9. 9Decide which type of filling you want to use. Each recipe makes enough to fill all the cookies.
10. 10To make the peanut butter filling: Mix all of the ingredients until smooth; a mini food processor works well here. If you're not using a food processor, sift the confectioners' sugar before stirring it together with the peanut butter and milk or half & half.
11. 11To make the fudge filling: Combine the chocolate chips and half & half in a small, microwave-safe bowl; or in a small saucepan. Heat until the half & half is steaming. Remove from the heat, and stir until the chips have melted and the filling is smooth; reheat briefly if necessary.
12. 12Spread the filling on half the cookies. Top with the remaining cookies.