Line an 8-inch square pan with a parchment sling, leaving overhang on two sides. Heat the oven to 325°F (160°C).
In a large bowl, whisk together the flour, baking powder, and sea salt. In a separate heatproof cup, whisk the warm soy milk with cocoa powder and espresso powder until smooth and glossy (this blooms the cocoa).
In another bowl, whisk the melted vegan butter, sugar, and vanilla for 30–60 seconds until it looks sandy and slightly dissolved. Whisk in the cocoa-milk mixture until evenly combined.
Add the dry ingredients to the cocoa mixture and fold with a spatula just until no dry flour remains. Let the batter rest for 5 minutes to hydrate, then spread into the prepared pan and smooth the top. Tap the pan firmly on the counter twice to release air.
Bake 28–32 minutes, until the edges are set and a toothpick inserted near the center emerges with a few moist crumbs. Cool the pan on a rack for 20 minutes, then place in the freezer for 10 minutes to firm the surface for the caramel.
Make the caramel while the brownies bake: In a small saucepan, combine the vegan condensed milk, vegan butter, brown sugar, and maple syrup. Cook over medium heat, stirring, until everything melts together. Continue to cook at a gentle simmer for 8–10 minutes, stirring often, until thickened and slightly darker (about 225°F/107°C on a thermometer). Stir in the sea salt and let stand 3 minutes to thicken slightly.
Pour the warm caramel over the cooled, slightly chilled brownie layer and spread to the edges. Refrigerate 30–40 minutes, until the surface is tacky but not runny.
For the ganache, place the chocolate chips and coconut oil in a medium bowl. Heat the coconut cream in a small pot until steaming with small bubbles at the edges (do not boil), then pour over the chocolate. Let sit 2 minutes, then whisk until smooth and shiny. Let the ganache cool 10 minutes to thicken slightly.
Spread the ganache over the caramel, tilting the pan to level. Chill 45–60 minutes, until the chocolate is set but not rock hard. Sprinkle with flaky sea salt when the ganache is just tacky so it adheres without melting.
Lift out using the parchment sling, warm a knife under hot water, wipe dry, and cut into 16 squares, wiping the blade between cuts for clean layers.