Preheat the oven to 350°F (175°C). Grease the cake pan and line it with parchment paper.
In a large bowl, combine gluten-free flour, cocoa powder, sugar, baking powder, baking soda, salt, and instant coffee.
In a medium bowl, whisk almond milk, oil, eggs, and vanilla extract until smooth.
Gradually add the wet mixture to the dry ingredients. Stir gently until just combined.
Pour in the cooled brewed coffee, mixing until smooth.
Fold in the dark chocolate chips.
Transfer the batter to the prepared pan. Smooth the top with a spatula.
Bake for 40 minutes or until a toothpick inserted in the center comes out clean.
Let the cake cool in the pan for 15 minutes before transferring to a wire rack.