Guava-Filled Tarta Cake - Presto self-rising

Method

• Mix butter and 2 eggs with spoon (no electric mixers) until smooth. Add sugar and mix well. Add flour 1/2 cup at a time and continue to mix well. The batter is thick, not runny. You can add a little milk and vanilla, but make sure it is a thick pasty batter.
• Divide cake batter in 1/2. Using an 8" square aluminum cake pan (no glass), line bottom with wax paper or butter and flour bottom of pan. Spread 1/2 batter on bottom of pan. This portion should be 1/2" thick. (Bottom portion should be thicker than top portion.)
• Use only guava paste (no membrillo or jam/jelly) thinly sliced. Place guava on bottom portion of cake mix until it is completely covered. Cover guava paste with remaining cake batter. Spread evenly until guava is completely covered.
• Preheat oven to 300 degrees. Cook for at least an hour. You will know it is done when it is brown on the top and when you insert a fork it comes out clean. Do not overcook or it will be too dry.