Cream the fats and sugars: In a large bowl, beat 1/2 cup unsalted butter and 3/4 cup creamy peanut butter until smooth and fluffy, about 2 minutes. Add 1/2 cup brown sugar and 1/3 cup granulated sugar.
Beat until light and creamy.
Add egg and vanilla: Mix in 1 large egg and 1 teaspoon vanilla extract until well combined. Scrape down the bowl to catch any pockets of peanut butter.
Combine dry ingredients: In a separate bowl, whisk 1 1/4 cups all-purpose flour, 1/2 teaspoon baking soda, and 1/4 teaspoon fine salt.
Bring the dough together: Add the dry mixture to the wet ingredients. Mix on low just until no streaks of flour remain.
The dough should be soft but not sticky.
Chill briefly: Cover and chill for 20–30 minutes. This helps the cookies keep their chewy centers and prevents overspreading.
Preheat and prep: Heat the oven to 350°F (175°C). Line two baking sheets with parchment.
Portion and shape: Scoop heaping tablespoon portions (about 1 1/2 tablespoons each).
Roll into balls and place 2 inches apart. Gently flatten the tops with your fingers to about 3/4-inch thick for even baking.
Bake: Bake 9–11 minutes, until the edges look set and the centers are slightly soft and puffy. Do not overbake—carryover heat will finish them.
Cool completely: Let cookies rest on the sheet for 5 minutes, then move to a rack to cool fully.
They must be cool before dipping.
Melt the chocolate: In a microwave-safe bowl, melt 1 1/4 cups semi-sweet chocolate chips with 1 teaspoon coconut oil in 20–30 second bursts, stirring between each until smooth. Or use a double boiler.
Dip and decorate: Dip each cooled cookie halfway into the chocolate. Let excess drip off.
Place on parchment and, if desired, sprinkle with a pinch of flaky sea salt or chopped peanuts.
Set and serve: Let the chocolate set at room temperature (30–60 minutes) or refrigerate for 10–15 minutes. Enjoy once firm.