01 - Preheat oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, leaving an overhang for lifting.
02 - In a heatproof bowl, combine butter and chocolate chips. Melt in the microwave in 30-second intervals or over a bain-marie, stirring until smooth. Let cool slightly.
03 - Whisk the sugar, eggs, and vanilla extract into the melted chocolate mixture until fully incorporated.
04 - Fold in flour and salt until just combined. Set aside.
05 - In a separate bowl, beat softened cream cheese and sugar until smooth and creamy.
06 - Add egg, flour, matcha powder, and vanilla extract to the cream cheese mixture. Beat until completely smooth.
07 - Spread approximately two-thirds of the brownie batter into the prepared pan. Spoon dollops of matcha cheesecake mixture over the brownie layer. Add the remaining brownie batter in between the cheesecake dollops.
08 - Using a skewer or knife, gently swirl the brownie and cheesecake mixtures together to achieve a marbled effect.
09 - Bake for 35 minutes, or until the edges are set and the center is just slightly jiggly.
10 - Allow to cool completely in the pan. Lift out using the parchment overhang and slice into squares.