Preheat the oven to 350°F / 175°C. Grease and line an 8-inch / 20cm square cake pan with parchment paper, so it goes up the sides like a sling.
In a small bowl, whisk together the spelt, almond meal, cocoa powder, baking powder, and salt. Set aside.
In a saucepan, bring the oil to a simmer, turn off the heat, and add the chopped chocolate. Swirl the pan to cover the chocolate and allow it to sit for 2 minutes. Whisk until smooth.
In a large bowl, whisk the egg, egg yolk, zucchini, honey, and vanilla until well combined. Whisk in the melted chocolate mixture, then fold in the dry ingredients with a rubber spatula. Stir in the walnuts and carob chips (if using). Spread in the prepared pan.
Make the cream cheese swirl: In a small bowl (I reuse the one I used for the dry ingredients), combine the cream cheese, honey, vanilla, and salt. Using a spoon, drizzle lines of the cream cheese mixture over the brownie layer, then use a knife to swirl the two layers together.
Bake in the middle of the oven for 20 to 22 minutes, until a tester comes out with wet crumbs and the brownies are still a bit wobbly in the center. Do not overbake, or the brownies will be too dry.
Cool completely in the pan, then cut into squares.
