Preheat the oven to 180°C / 350°F. Grease one 22 cm tube pan thoroughly.

Combine 100 g melted unsalted butter, 150 g chopped walnuts, 100 g brown sugar, and 80 g honey in a mixing bowl. Stir in 1 tsp mixed spice and 1 tsp vanilla extract.

Rest the walnut mixture for 3 min until slightly thickened. Spread it evenly across the bottom of the greased tube pan.

Beat 150 g softened unsalted butter with 200 g granulated sugar until pale and fluffy. Beat in the remaining 1 tsp vanilla extract.

Add the 3 eggs one at a time. Beat well after each addition.

Sift 230 g wheat flour, 1 tsp baking powder, and the pinch of salt together. Reserve the dry mixture.

Add one third of the dry mixture to the butter mixture and mix briefly. Add half of the 120 ml whole milk and mix briefly.

Repeat the alternating additions of the remaining dry mixture and milk. Mix only until the batter is smooth.

Spoon the batter gently over the walnut layer. Level the surface without disturbing the topping.

Bake at 180°C / 350°F for about 45 min until a skewer comes out clean. Cool in the pan for 15 min.

Invert the cake onto a serving plate while warm. Let it cool completely before slicing.