Apple Jelly Layer Cake - Testing

https://food52.com/recipes/23704-old-fashioned-apple-jelly-cake

2 cup sugar (425g) (I want to try decreasing to 400g)

3 1/2 cup flour (525?g)

1 Tbsp baking powder

228g/1 cup butter, cut into pieces

5 eggs

1 cup milk

1 Tbsp vanilla 

500-600g apple jelly

1. Prepare four 8" cake pans by buttering them.
2. In a mixer bowl, combine all the dry ingredients and mix thoroughly.
3. Gradually blend the butter in until thoroughly combined - it will look like rough sand. 
4. Add the eggs one at a time before adding the milk slowly, and finally the vanilla.
5. Divide the cake batter into four equal portions (about 410g) and pour into the cake pans. 
6. Bake at 325F for 15-20 minutes per layer, or until layers are golden around the edges and a toothpick comes out clean. 
7. Allow layers to cool a bit in the pan, then turn out onto a clean dish towel or cooling rack.
8. While the layers are still warm, put the first layer on a serving platter. Spread a layer of the apple jelly (I SHOULD KNOW THE WEIGHT), apply the next layer and repeat until you put the fourth layer on. (I did 100g between layers (300) and 300 around, but I have the wrong cake tins and it's all very uneven and funny looking and also makes it difficult to know how much I actually need for the exterior).
9. Spread the rest of the jelly over the entire cake. Let it cool completely before serving.