Preheat the oven to 350°F (180°C). Lightly grease a 9x9 inches/23x23cm square pan with oil or vegan butter. Then line the pan with a strip of parchment paper.
To a medium-size mixing bowl, add all-purpose flour, granulated sugar, cocoa powder, baking powder, and a pinch of sea salt, and whisk to combine. Add soft vegan butter and almond milk and mix with your hands to a firm dough. Then place it in the freezer for 30-40 minutes to set.
To high-speed blender or food processor, add extra-firm tofu, granulated sugar, almond milk, vanilla extract or vanilla sugar, rum, lemon juice, and lemon zest, and blend on high speed until smooth and creamy.
Put 2/3 of the dough into the pan and press it evenly to the sides. Use the bottom of the measuring cup or spoon to flatten it and smooth the top. Pour the cheesecake filling and smooth it evenly. Then grate or crumble the remaining dough over the top of the cheesecake filling.
Bake in the preheated oven for 30 minutes or until the edges separate from the pan. Let cool completely before serving.
Cut into bars, dust with powdered sugar, and enjoy!