Mint Chocolate Brownies

I made these brownies last night. They were really good, but didn't quite turn out as I expected. I got this from Martha Stewart and not only did I use the recipe from her website, I also watched the video of some guy making these. The brownies in the picture and in the video show big white chunks of the mint. I baked the brownies for only 45 minutes of the 55 minutes and the mint melted into the batter (you could barely see any white). So I'm not really sure where I went wrong - not to say they didn't taste amazing, but I really would've liked to see the big mint chunks.

Mint Chocolate Brownies

8 tbsp (1 stick) unsalted butter, plus more for pan
8 oz semisweet or bittersweet chocolate, chopped
1 cup sugar
3/4 tsp salt
3 large eggs
1/2 cup all-purpose flour (spooned and leveled)
1/4 cup unsweetened cocoa powder
25 small (1 1/2 inch) peppermint patties

Preheat oven to 350 degrees.

Line an 8-inch square baking pan with aluminum foil, leaving an overhang on all sides; butter foil. Set aside.

Place chocolate and butter in a medium heatproof bowl set over (not in) a saucepan of gently simmering water. Stir occasionally just until melted, 4 to 5 minutes.

Remove from heat. Whisk in sugar and salt until smooth; whisk in eggs. Gently whisk in flour and cocoa powder just until smooth (do not over mix).

Spread 1/3 of batter in prepared pan. Arrange peppermint patties on batter in a single layer, leaving a narrow border on all sides. Top with remaining batter, and smooth surface. Bake until a toothpick inserted in center comes out with moist crumbs attached, 45 to 55 minutes.

Cool completely in pan. Use foil to lift from pan; peel off foil and discard. Cut into 16 squares (4 rows by 4 rows).