Preheat oven to 350° F. Grease a 9 x 9-inch baking pan with butter and lightly dust with flour. Run a sink-full of warm soapy water to toss dirty utensils in as you go (optional, but helpful)
Cream together room temperature (softened) butter and sugar in a stand mixer fitted with the paddle attachment, at medium speed until light and fluffy (about 2 minutes). If butter is not at room temp, heat slightly in microwave (about 30 seconds), and stir/whisk until smooth. Do not add hot butter to sugar, let it cool slightly.
3/4 cup unsalted butter, 1 1/4 cup sugar
Add eggs one at a time, mixing well after each addition. Add vanilla and coffee powder and beat until combined.
In a medium bowl, sift together flour, cocoa powder, baking powder and salt. Add dry ingredients to mixer, a cup at a time to avoid the flour flying out of the bowl, and mix on low speed until just combined. Do not over-mix. Fold in chocolate chips with a mixing spoon.
1 1/2 cup all-purpose flour, 3/4 cup cocoa powder, 1 tsp baking powder, 1/2 tsp salt, 1/2 cup chocolate chips
Spread the dough evenly into the prepared baking pan, making sure it gets into the corners of the pan. Spoon the jam over the top of the brownie batter, as evenly as possible. Swirl the dough into the batter with a butter knife, making sure that it gets deep inside of the batter.
1/2 cup strawberry or raspberry preserves
Smooth out the top of the batter and bake in preheated oven for 35-40 minutes, until a knife inserted into the brownies comes out clean. Test for doneness in several areas, as you may get a false positive if you insert knife into the strawberry jam. Cool completely before frosting.
For the Frosting:
Place sugar in a stand mixer fitted with the paddle attachment, and add butter in 2 Tbsp increments (to avoid mess), mixing for about 2 minutes on low speed.
2 cups powdered sugar, 1/2 c. 8 Tbsp butter, unsalted and at room temp.
Add vanilla and mix another 2 minutes on low speed.
1 tsp pure vanilla extract
Add salt and heavy cream and mix on med-high until soft and fluffy, about 2 more minutes.
Pinch of salt, 2-3 Tbsp heavy cream
Add rosewater and food coloring ( a drop at a time until you get the pink you desire), and mix until just blended.