Line an 8x8-inch baking dish with parchment paper. Set aside.

Into a large mixing bowl, add the butter, granulated sugar, and brown sugar. Use a hand mixer on medium speed to cream together the butter and sugars together.

Add the peanut butter and continue mixing until fully incorporated and consistency is smooth.

Add the all-purpose flour, vanilla extract, salt, and oats. Mix just until combined.

Stir in 1/2 cup of chocolate candies.

Press the cookie dough mixture into the prepared baking dish. Set aside.

In a microwave-safe bowl, combine the chocolate chips and heavy cream. Use the microwave to heat the chocolate in 20-second intervals, stirring after each interval until the chocolate is melted and its consistency is smooth.

Pour the melted chocolate over the top of the cookie dough mixture, using a spatula to spread the chocolate so that it covers the entire surface.

Sprinkle with the remaining 1/4 cup of chocolate candies.

Cover and refrigerate until set, at least 2 hours, then cut into squares and serve.