Preheat oven to 350 degrees. While the oven is preheating, combine flour, unsweetened cocoa powder and salt in a medium sized bowl and set aside.
Combine the melted butter, brown sugar, and granulated sugar in a large bowl. Using the whisk attachment mix with a hand or stand mixer on medium for 2 minutes. Add in the eggs, olive oil and vanilla extract and continue whisking for another 2 minutes.
Sift the flour, unsweetened cocoa powder and salt. Fold in the sifted dry ingredients and the chocolate chips with the sugars, butter, oil. eggs and vanilla extract mix until just combined. Do not over stir!
Pour batter into a 8x8 parchment paper lined pan and cook on the top rack for 20-25 minutes.* Once brownies are finished drizzle with chocolate. Cut into 9 large brownies and serve warm. Enjoy!
Place the white chocolate in a small bowl and microwave on high for 30 seconds. Remove and stir and microwave an addition 10 seconds if not completely melted. Repeat this process with the semi-sweet chocolate in a separate bowl.
Immediately drizzle the warm chocolates over the cooked brownies and use a butter knife to swirl them together.
*I find that cooking these at 23 Minutes gets me the best results. You may need to cook the brownies a little more or less depending on your oven.Also, if you would like to tone down the chocolate swap out the chocolate chips for sliced almonds, dried fruit or walnuts! You could also add on a caramel drizzle to the top!