While preheating oven to 350F, butter a 13" x 9" x 2" baking pan.
Melt butter and chocolate in a large, saucepan over low heat, stirring until smooth.
Remove from heat and stir in sugar, eggs and vanilla.
Mix flour, baking powder and salt in a small bowl.
Add chocolate mixture and whisk to blend. Stir in nuts.
Pour two cups of batter in pan and spread to even layer. Freeze until firm, about 10 minutes.
Spread our organic Fiordifrutta Strawberry over partially frozen brownie batter pan and gently spread remaining batter over top and let stand 10 minutes to thaw.
Bake brownies until tester inserted into center comes out clean, about 35 minutes. Transfer to rack and cool.
Cut brownies into squares and enjoy!