Line a 9x13 inch baking pan with foil. Leave enough foil at the edges of the pan so you can lift out the candy (similar to fudge).
Preheat the oven to 350 degrees.
Beat butter, egg yolk, peanut butter, and sugar on medium speed until the mixture is creamy and smooth.
Add in the flour, oats, and salt to the mixture and beat on low until the ingredients are combined.
Press the mixture into the bottom of the pan. Bake the crust for 15 to 20 minutes or until light golden brown in color.
Remove the pan from the oven and scatter the chocolate and peanut butter chips over the crust. Return to the oven and let it cook for another 1-2 minutes until the chips begin to melt.
Remove the pan and use a spatula to spread the chocolate and peanut butter over the crust evenly. The chocolate chips and peanut butter chips will finish melting while you spread.
Finally, sprinkle the English toffee bits over the melted chips and gently press them into place. Be careful because the melted chips are hot.
Let the pan cool for several hours until the chocolate and peanut butter has set. Use the foil to lift the candy from the pan.
Cut toffee into desired shapes and store in an airtight container.