Preheat the oven to 350°F. Grease a 9x5-inch loaf pan.

Drain the 20-ounce can of diced pineapple in a colander, press to remove excess liquid, and chop the pieces a little smaller if desired. Set aside.

In a large mixing bowl, break the 7 ounces marzipan into pieces and add the 3/4 cup room-temperature unsalted butter. Beat with an electric mixer on medium speed until combined and smooth.

Add the 3/4 cup granulated sugar and 1 teaspoon quality pure vanilla extract (and 1 teaspoon pineapple extract if using). Beat until incorporated.

Add the 3 large eggs one at a time, beating until each egg is incorporated before adding the next.

In a separate bowl, whisk together 2 cups all-purpose flour, 2 teaspoons baking powder, and 1/4 teaspoon salt.

Add the dry ingredients to the wet batter and beat on low speed just until no streaks of flour remain (do not overmix).

Fold the drained, chopped pineapple into the batter with a spatula until evenly distributed.

Spread the batter into the greased 9x5-inch loaf pan and smooth the top.

Bake on the middle rack for 65–75 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the cake cool in the pan for 10 minutes, then remove it from the pan and place it on a wire rack to cool completely.

For the chocolate glaze: place 7 ounces chopped dark chocolate and 2 teaspoons coconut oil in a microwave-safe bowl. Microwave in 20–30 second intervals, stirring between each, until the chocolate is melted and smooth.

Spread the chocolate glaze evenly over the top and sides of the cooled cake. Place the cake in a cool place until the glaze is set.

Slice and serve.