Walnut Cake with Streusel

Preparation

1. Prepare the streusel by mixing the brown sugar, finely chopped walnuts, chocolate chips, cocoa powder, and cinnamon in a bowl. Set aside.
2. In a large bowl, mix the flour, cornstarch, and baking powder and sift to avoid lumps.
3. Cream the room temperature butter with the sugar and salt until the mixture whitens and becomes fluffy. This will take about 6 minutes with an electric mixer at medium speed.
4. In another container, beat the whole eggs together with the yogurt, lemon juice, and vanilla extract until you obtain a homogeneous mixture.
5. Incorporate the butter and the sifted ingredients alternately in three additions, gently folding with a spatula after each addition.
6. Add 1/3 of the butter to the liquid mixture and mix until integrated.
7. Add 1/3 of the sifted flour and mix until integrated.
8. Add another 1/3 of the butter and mix until completely incorporated.
9. Add another 1/3 of the flour and mix until homogenized.
10. Add the remaining butter and mix until the mixture is uniform.
11. Finally add the last third of the flour and mix until you obtain a smooth, lump-free batter.
12. Grease the mold with butter and pour in half of the prepared batter.
13. Sprinkle the prepared streusel over the batter in the mold.
14. Finish filling the mold with the second half of the batter.
15. Using a knife, gently stir the batter with circular motions to distribute the streusel.
16. Allow the dough to rest in the mold for 1 hour at room temperature.
17. When there are 30 minutes remaining before baking, preheat the oven to 180ºC.
18. Bake the cake in the preheated oven at 180ºC for approximately 45 minutes, checking if a skewer comes out clean to ensure it is cooked.
19. Let the cake cool in the mold placed on a wire rack to cool evenly.