Preheat the oven to 350 degrees F.

In a mixer with a paddle attachment, combine the sugars, butter and peanut butter. Beat until light and fluffy, about 3 minutes. Add the eggs, one at a time, beating after each addition. Sift together the flour, the baking soda and the salt and add to the dough. Dough should be stiff enough to shape with your hands. Make 1-inch balls and place on a lightly greased cookie sheet. Gently press thumb into the balls to flatten the cookies slightly and make an indentation in the center of the cookie. Press 3 or 4 chocolate chips into the indentation.

Bake for 15 to 20 minutes, or until lightly golden brown. Remove cookies from the oven and transfer to wire racks to cool.