For the Peanut Butter Cookies

1. Preheat your oven to 350 degrees Fahrenheit. Line baking sheets with parchment paper to ensure the cookies come off cleanly and in one pieces after baking.
2. In a medium bowl, whisk all purpose flour, baking soda, and salt together.
3. In a large bowl with a hand mixer or in the bowl of your stand mixer fitted with a paddle attachment, beat room temperature butter, light brown sugar, and 1/3 cup granulated sugar together on medium-high speed until smooth, creamy, and fluffy. This should be 2-3 minutes of consistent mixing.
4. Add room temperature eggs to the dough and beat on medium speed until incorporated.
5. Mix vanilla extract and creamy peanut butter into the dough on medium speed until smooth. Scrape down the sides and bottom of the bowl with a rubber spatula before mixing again to make sure the ingredients are properly incorporated.
6. Carefully, add the dry ingredients to your wet batter on low speed and in several additions to avoid making a mess. Mix only until you see the dry ingredients disappear into the batter, as mixing past this point can create dense cookies.
7. Roll the balls into 1 tablespoon-sized (35g) dough balls. Roll each ball in the extra 1/4 cup of sugar before placing them on the baking sheet. 
8. Bake the cookies for 8-12 minutes or until the tops are cracked, the centers look domed and slightly soft, and the edges are light golden brown.
9. Let the cookies cool on the baking sheet for about 5 minutes before transferring them to a cooling rack or plate to finish cooling.

For the Strawberry Jam Frosting

1. In a large bowl with a hand mixer or in the bowl of a stand mixer fitted with a paddle attachment, beat room temperature butter on medium-high speed until smooth.
2. Slowly, add powdered sugar to the mixture, beating on low speed to avoid the powdered sugar spilling out of the bowl. Once the powdered sugar is fully incorporated, beat for another minute to ensure the mixture is smooth.
3. Add the room temperature strawberry preserves to the frosting. Beat until combined. Scrape down the sides and the bottom of the bowl with a rubber spatula to ensure the ingredients are properly incorporated throughout.
4. If desired, transfer the frosting to a piping bag or a zippable plastic bag with the corner snipped off for better control.

For Assembly

1. Top half of your cooled peanut butter cookies with the strawberry jam frosting.
2. Heat 1/3 cup (107g) of strawberry preserves in the microwave for about 10 seconds before stirring aggressively with a spoon to smooth it out. If desired, transfer the jam to a piping bag or zippable plastic bag with part of the corner snipped off for more control. 
3. Top each frosted cookie with a dollop of strawberry jam as desired. For cleaner cookies, keep the jam towards the center of the cookie.
4. Add an unfrosted cookie to the top of each frosted and topped cookie to create a cookie sandwich.
5. For best results, allow the sandwiches to rest to firm up before storing at room temperature tightly covered or in an airtight container for up to 4 days.