Preheat oven to 350°F (180°C) and grease a mini muffin tin. In a microwave-safe bowl, add the chocolate and butter.
Melt the chocolate and butter in the microwave, using 20 second intervals, stirring between each. Generally, 40 seconds total is sufficient. Set aside to cool.
Into another large bowl (or bowl of a stand mixer), add the sugar and eggs.
Using a hand or stand mixer, beat the sugar and eggs together until pale and fluffy, approximately 3 – 5 minutes.
Stir the melted chocolate mixture, vanilla and espresso powder into the egg and sugar mixture and stir until fully incorporated.
Sift the oat flour, corn starch, cocoa powder, baking powder and salt into the chocolate mixture. Using a spatula, gently stir the mixture until no clumps remain.
Using a small cookie scoop, or 2 tablespoons, add a tablespoon of batter to each mini muffin cup.
Bake for about 15 minutes, or until a cake tester inserted in the centre comes out with a few moist crumbs attached. Let cool in pan on cooling rack.
To make the frosting, add the cream cheese to a large bowl (or bowl of a stand mixer), and using a hand mixer or stand mixer on medium, beat until creamy, about 30 seconds. Add in the sugar, vanilla and salt and beat until well combined. Slowly drizzle in the cold cream. Once combined, increase the mixer to high and whip until light and fluffy, about 2 minutes.
To assemble, pipe or dollop and tablespoon of frosting onto each brownie and top with a cherry.