Preheat your oven to 350 degrees F and line an 8x8in baking pan with parchment paper, leaving enough overhang for easy release later on. Spray with a nonstick spray and set aside.
Combine the butter and chocolate in a saucepan set over medium low heat. Stir continuously as both ingredients melt. Once smooth, remove from heat and transfer to a large bowl.
To the bowl, whisk in the sugars until smooth and creamy. Add each egg, one at a time, whisking after each addition. Whisk in the beer, vanilla and salt. Fold in the flour until just moistened and pour into the prepared baking pan. Smooth out the top with an offset spatula.
Bake the brownies for 25-30 minutes or until a toothpick comes out clean. Remove from heat and allow to cool completely at room temperature.
While the brownies are baking, prepare the buttercream. In the bowl of your stand mixer, add the butter, strawberry preserves, vanilla extract, strawberry extract, salt, and confectioner's sugar. Mix until all of the ingredients are thoroughly combined.
Once the brownies are cool, frost and decorate the top of your brownies. Add fresh strawberries if desired. Enjoy!