Preheat oven to 350°F. In a 10-inch cast-iron skillet, cook ginger, ½ cup (113 grams) butter, and 3 tablespoons honey over medium heat, stirring constantly, about 5 minutes. Transfer mixture to a large bowl, reserving 2 tablespoons mixture in skillet.
Add curry, remaining 2⅓ tablespoons honey, and remaining ¼ cup (57 grams) butter to pan, and cook until bubbly. Remove from heat; arrange pineapple in a pinwheel fashion around pan.
In a small bowl, whisk together flour and baking powder. To ginger mixture, add sugar, and beat with a mixer at medium speed until fluffy. Add eggs, one at a time, beating well after each addition. Gradually add flour mixture to ginger mixture alternately with milk, beginning and ending with flour mixture, beating just until combined after each addition. Stir in vanilla. Spoon over pineapple, using a spatula to smooth batter to edges of skillet.
Bake until a wooden pick inserted in center comes out clean, 28 to 30 minutes. Let cool in pan for 10 minutes. Invert cake onto a serving plate. Drizzle with remaining syrup from pan, and serve warm.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/pineapple-upside-down-cake/