Cover cookie sheet with waxed paper or parchment for easy release once bark has hardened.

In a microwave safe bowl, heat peanut butter and white chocolate chips in microwave until melted (30 seconds at a time, stirring in between--should take about 1 1/2 minutes). Stir until smooth.

In another microwave safe bowl, heat chocolate chips in microwave until melted. (30 seconds at a time stirring in between-- should only take about 1 to 1 1/2 minutes).  Stir until smooth.  Make sure you don't overheat the chocolate or it will burn and become hard.

Once chocolate mixtures are melted and smooth, pour most of the peanut butter mixture on prepared cookie sheet. Spread until thin and even

Add regular chocolate in large spoonfuls or lines to the top of the peanut butter mixture.  Add remaining peanut butter mixture to the top of the regular chocolate.

Using a butter knife, swirl the two chocolates back and forth or in circular motions until you reach your desired look.

Allow bark to cool and harden.  Break bark into whatever size you desire or cut into squares.