Perfectly Moist Truffle Cake with Melted Chocolate Buttercream

Ingredients For the Cake: 2 large eggs A pinch of salt 200g granulated sugar (1 cup) 10g baking powder ( 2 tsp) 50g cocoa powder ( 1/2 cup) 220g all-purpose flour ( 1 3/4 cups) 70ml vegetable oil ( 1/4 cup) 70ml milk ( 1/4 cup 1 tbsp) 150ml hot water ( 2/3 cup) For the Buttercream: 200g unsalted butter, at room temperature ( 1 cup ) 50g powdered sugar (1/3 cup) 100g melted dark chocolate ( 3.5 oz ) Instructions For the Cake: Preheat the Oven: Preheat your oven to 175°C (350°F). Grease and line a 16 cm (6-inch) round cake pan with parchment paper. Mix Dry Ingredients: In a medium bowl, sift together the flour, cocoa powder, baking powder, and salt. Mix Wet Ingredients: In a large mixing bowl, beat the eggs and sugar together until light and fluffy. Combine Ingredients: Gradually add the dry ingredients to the wet mixture, mixing until well the vegetable oil and milk, and mix well. Pour in the hot water and mix until the batter is s