Over a double broiler or in a large microwave safe bowl, melt butter and semi-sweet chocolate together. If melting in the microwave, melt in 30-second increments, stirring after each hit in the microwave. Once the chocolate has melted, allow the mixture to cool 8-10 minutes.
After the chocolate has cooled slightly, add in the granulated sugar and eggs. With a whisk or rubber spatula, mix in the sugar and eggs very well.
Next, add in the vanilla extract and espresso powder. Mix until combined.
Add in all purpose flour, salt, baking powder, and unsweetened cocoa powder. Stir until well combined.
Add in canola oil, and stir until combined.
Lastly, add in 1 cup of milk chocolate chips. Stir until combined.
Spread the brownie batter into your prepared baking pan. Sprinkle 1/4 cup of semi-sweet chocolate chips over the top of the batter. With your rubber spatula, press the semi-sweet chocolate chips into the brownie batter and give the batter a final spread, making sure it’s in an even layer in the baking dish.
Bake for 25- 30 minutes, or until a cake tester comes out clean with just a few fudgy crumbs stuck to it. Allow to cool completely.
Using a hand mixer or a stand mixer, beat the unsalted butter in a large bowl on medium speed until it is very light and fluffy, about 2-3 minutes. This makes for a very fluffy frosting.
Next, gradually add in the powdered sugar, 1 cup at a time, beginning with 3 cups (reserve the remaining cup for later).
Add in the heavy whipping cream, beginning with 3 Tbsp. Beat until well combined.
Next, add in the crushed freeze-dried strawberries, mixing until well combined.
If the frosting seems too thin, add in the remaining cup of powdered sugar, beginning with 1/2 cup. If the frosting seems too thick, add in the remaining heavy cream.
Lastly, add in a pinch of salt to offset the sweetness (optional), and a couple drops of food coloring, if desired. Mix until well combined. Spread on top of the cooled brownies in an even layer.
*You can crush the freeze dried strawberries in a food processor, or you can put them in a ziplock bag and use a rolling pin to crush them.