Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.
In a large mixing bowl, combine 1 cup creamy peanut butter, 1 cup granulated sugar, 1 large egg, and 1 teaspoon baking soda. Mix until all ingredients are fully incorporated and form a smooth dough.
Roll the dough into 24 equal-sized balls, about 1 inch in diameter, and place them evenly spaced on the prepared baking sheets.
Using your thumb or the back of a small spoon, gently press an indentation into the center of each dough ball to create a well for the jelly.
Fill each indentation with about 1/2 teaspoon of strawberry jelly, being careful not to overfill to prevent spilling during baking.
Bake the cookies in the preheated oven for 10 to 12 minutes, or until the edges are lightly golden but the centers remain soft.
Remove the cookies from the oven and allow them to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.